Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: uniquorn on October 04, 2018, 01:05:42 PM

Title: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 04, 2018, 01:05:42 PM
I thought this topic needed a dedicated thread as comments tend to get lost in the freezing/melting season threads. Fish Out of Water noticed a rapid increase in salinity at 300m on the Mercator Ocean model and questions were raised as to it's validity. Snips and links below
Update on Mercator 300m salinity, aug1-sep30. (every 2days, scale is not static)
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180801/20180930/2/4

Is this still real? And if so, any explanations?

If it was a Kelvin wave from the deep waters, this could change the whole dynamic of the arctic: lowering freezing temps, holding more heat in summer, drawing up a long chain of warmer water? and likely half hidden under the existing pack as it looks to only show around the edges!  Wondering if the 'bobbing effect' of so many smaller bergs might serves as a pump to circulate itself.
<snippage> another possibility is that the saline water is moving across the Beaufort at depth and is backing up in the direction it's coming from and merely leaking into the Beaufort gyre following the shelf bathymetry. That is it's Atl. water.
<snippage>
I think the wind shift caused a coastal Kelvin wave of shoaling of warm salty Atlantic water from depths below 300m up to the 300m level. I have forgotten who suggested it was a Kelvin wave, but I think that's correct because shifts in wind regimes can cause coastal Kelvin waves.
Extraordinary amounts of warm salty Pacific water have been flowing towards the Barrow submarine canyon, but that water hasn't had the time to reach the CAA and loops show that that water may be rotating clockwise towards the Chukchi shelf margins, not the CAA. The warm water that's sinking in the Chukchi region will likely store heat in the water layers above 300m.
<snippage>
Is it likely that long distance waves and, to some extent, tidal movements have been suppressed by thick pack ice and that, as the percentage of open water increases, we will begin to see evidence of larger scale 'bottom mixing' as well as more localised storm driven 'top mixing' of arctic waters?
As the Windy wave image shows, the damping effect of arctic ice appears to be diminishing.
Mercator 300m salinity and temperature, aug1-oct4.
Windy ecmwf waves and SST, oct4
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 05, 2018, 12:00:13 AM
A great bathymetry map from NOAA. It uses very different bright colours that are easily distinguishable, even in small images.
Another one with names that will be helpful (for me, at least)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 05, 2018, 12:25:13 AM
We can go back further to see where it starts but salinity is already high at 300m near the alaskan coast at the beginning of august. It builds up rapidly in the Beaufort Sea, west of the CAA, near the Mclure Strait. FOoA suggests that it's too fast to be flowing around the coast so it is probably 'upwelling' from saltier water below. (I'm not sure how a kelvin wave does this yet)
There is also a salinity build up west of the Chukchi Plateau which I find easier to understand as it would appear to be incoming salty pacific water sinking as soon as it reaches deeper water.

The changes on the Mercator temperature chart are more subtle but there is a noticable increase in both higher salinity areas, especially west of the Chukchi plateau.

Interesting how much activity there is in the Fram Strait at 300m
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on October 05, 2018, 11:48:48 AM
I've modified my take a little, looking at Mercators various offerings it's clear there's no temperature build up associated with the salinity increase at the base of Amundsen gulf, so I think that it's a deeper layer being forced in that direction, a combination of Atl. water penetration past Lomonosov into the Pacific/Canadian side and the tidal movements of Amundsen.
   It looks, to me, that Amundsens tidal movements are what drives the Beaufort gyre, which can rotate either way. Depending on weather conditions, at at the beggining of melt, the start up decides which way the gyre rotates in any given year. For instance I'd guess a high over the north Pacific with a low in the Pacific Arctic may force a surge of Pacific water north and that turning along the coast would force the gyre to kick start ccw.
   My ball-park maths suggest 1-200km3 of turnover in Amundsen twice a day, this year it's driving a current across the north coast of continental America, it seems at all depths. It carries any ice with a keel towards the 'blob' where it gets caught in the eddies where this coastal current turns the incoming Pacific waters west. The incoming Pacific waters are backed up and fall instead into the Chukchi abyssal plain where they appear to be met by Atl. waters.
 The easiest fraction of water to draw into the Gulf are the surface waters and since the flow has, i think, been enhanced by Atl. influx as shows in this current Beaufort hycom  (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortictn_nowcast_anim30d.gif)
 
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on October 05, 2018, 01:26:39 PM
Just an ignorant question: Is there any buoy or float in that area that can verify that the anomaly is actually there? I keep wondering at Mercator's animations (and Hycom's) what the actual level of data behind them.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 05, 2018, 06:16:02 PM
Thanks johnm33, shame to see that thick ice going into the Mclure Strait.
Oren, yes, thanks to Bruce Steele, but it will take me a while and a steep learning curve to verify if they match up.
There are two new ITP buoys in the Beaufort, ITP 109 and 110. They both seem to be working and sending out temperature / salinity numbers.

http://www.whoi.edu/page.do?pid=163196

ITP110 data is here ftp://ftp.whoi.edu/whoinet/itpdata/itp110grddata.zip
edit: It starts at day263, sep20 2018, so will be useful going forward.
edit2: 300m looks like a layer boundary. Hopefully ITP110 will drift into the modelled higher salinity over the next few days. (based on johnm33 hycom gif above)
edit:The Ice-Tethered Profiler data were collected and made available by the Ice-Tethered Profiler Program (Toole et al., 2011; Krishfield et al., 2008) based at the Woods Hole Oceanographic Institution (http://www.whoi.edu/itp).
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on October 05, 2018, 11:36:22 PM
Thanks for the detective work uniquorn.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 06, 2018, 01:22:43 AM
Mercator 100m salinity, aug1-oct4.
This shows more clearly the flows that johnm33 describes (not the tides). Pacific water is less saline than the Atlantic but, according to the model they are meeting at 100m west of the Chukchi plateau.
The model also shows 'leakage' over the lomonosov ridge and a steady drift of higher salinity toward Greenland, which may have contributed to recent events in the Lincoln sea. This continues along the CAA to the Mclure Strait and possibly, at reduced salinity, all the way to the Amunsen Gulf.
FOoW is probably correct that none of these flows are rapid enough to explain the salinity rise at 300m so upwelling is prime candidate.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on October 06, 2018, 03:04:51 PM
Tidal effects are important but the Beaufort high is an atmospheric phenomenon not affected by ocean tides. The Beaufort high pressure area is what drives the clockwise rotation of the oceanic Beaufort gyre. When the high breaks down for weeks at a time and storms enter the region, the gyre weakens. Flow patterns change in the CAA and fresh water drains from the gyre into the CAA channels. That happened this summer.

When the high came back strong in late August and September clockwise winds caused coastal upwelling along the CAA and Alaskan continental shelves and convergence under the high pressure dome. Thus salinity increased in coastal areas where the Atlantic layer rose up in response to the wind shift and associated coastal upwelling.

Mercator also has animations of ocean currents at various layers and sea surface height anomalies. We can directly visualize what's happening at the surface by watching animations of ice movement as A-Team has shown us.

Remember that sea surface height gradients from the Pacific to the Arctic to the Labrador sea drive flows towards the Labrador sea where deep convection depresses sea surface heights.

Here's a link to Mercator's animation of currents in the 100m layer over the past 3 months or so.
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180701/20181004/3/3
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 06, 2018, 11:35:06 PM
Thanks FOoW. I struggled a bit with mercator current animations. The arrows are tricky to follow.
I did find their fixed scale salinity files though.
To my untrained eyes there isn't much supporting evidence for the 300m salinity rise at 30m so I'm posting 2018jan-oct for general background info and discussion.

Does the Mclure Strait low salinity 30m water sometimes flow up the Nares and round the top of Greenland??

tech note: this animation is created from Mercator fixed scale images but there is still some dithering on the scale (and probably within the images. This may be due to conversion from jpg to gif

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 07, 2018, 12:17:12 PM
I hope you don't mind if I quote your post here FOoW
The scientific literature reports that heat is not transported through the Bering strait. There is summer water in the Chukchi and Beaufort seas, but Pacific water was not found to transport heat to the Arctic ocean. That clearly is not the case this year.

Here's a link to the 30m temperature animation since July 1 this year. Heat is entering the Arctic from the Pacific through the Bering strait and it's going to be stored in the Pacific water layer below the surface. It will affect melting seasons in the years to come. It is too deep to lose it's all its heat over this winter. This is something new, beyond recent the report about heat that has been stored by sinking summer water in the Chukchi sea.

http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180701/20181004/1/2

If we start the animation from July 1 last year, we see a push of summer water into the Arctic through the Bering strait, but nothing like what we're seeing now in terms of heat transport into the Arctic ocean.

http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20170701/20181004/1/2
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on October 07, 2018, 04:16:36 PM
The Coriolis effect tends to cause water to deflect to the right side of channels and passageways into and out of the Arctic ocean. Thus most water that flows out of the CAA is unlikely to flow back into the Arctic through the Nares strait. That animation does show a surge of fresh water up the Nares strait but most of that fresh water likely came from Greenland meltwater in my opinion. Obviously, with all the complex loops, small gyres and tidal effects some CAA fresh water could spin back into the Nares.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 08, 2018, 04:01:44 PM
update on ITP110 profile contours. Looks like a salinity increase up to 450m....
http://www.whoi.edu/page.do?pid=163197
added location map
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 08, 2018, 04:36:18 PM
I'm a bit confused since ITP109 is already showing much higher salinity below ~300m
ITP109 and 110, location and T&S profile contours
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: SteveMDFP on October 08, 2018, 05:06:36 PM
I'm a bit confused since ITP109 is already showing much higher salinity below ~300m
ITP109 and 110, location and T&S profile contours

You're right of course.  It doesn't make sense that the profiles should look so different.
I'd hazard to guess that some malfunction started in buoy 110 fairly early on--the ?artifact? early in the 110 tracing leads me to that conclusion.

These profiles are often difficult to interpret.  What many of us might be most interested in is how the temperature and salinity profiles change year-over-year in various locations.  Damned near impossible to sort that out.

What's absolutely maddening is that relevant data to sort this out already exists.  The US has been sending nuclear subs through the arctic continuously since the 1950s.  They surely measure temperature (and probably salinity) as they go, along with depth.  But I'm quite sure the tracks of the nuclear sub movements are highly classified.  Grr.

It does seem the US military, and especially the Navy, has been taking climate change more seriously than any other branch of government.  I surmise that worrisome changes in these measurements have been noted for quite some time.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on October 08, 2018, 05:21:59 PM
Remember that there is a fresh water pool more or less centered under the atmospheric Beaufort high pressure area. When buoys move from the center of that pool towards the continental shelf the salinity increases through most or all of the profile. There may be glitches in the raw buoy reports but much of what we are seeing is explained by basic facts oceanographers already know about the Beaufort gyre and regional oceanography.

Our fundamental problem causing confusion here is that physical oceanography involves complex physics and most of us aren't experts.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 08, 2018, 07:24:32 PM
If it was a malfunction, wouldn't the temperature profile be similarly affected? Not if it's a sensor problem.
Remember that there is a fresh water pool more or less centered under the atmospheric Beaufort high pressure area. <snippage>
It looks like a deep pool but we should see if the sensor is ok in a few days.

Mercator Temperature 30m, jun2017-oct2018, every 7days. According to the model, heat was lost everywhere except North of Svalbard at 30m in 2017/18 freezing season. It looks like there is more heat in the Chukchi this year.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on October 08, 2018, 11:58:01 PM
Just a thought on the buoys, the deeper layers do not mix easily if a stream/current began to flow it may simply form it's own 'channel' on a deeper layer. Since I suspect the flow originates with 50%+ Pacific water falling into the Chukchi abyssal plain which rounds the Chukchi plateau before heading east that would fit. I think.
The animation at 9 above seems to be showing the circulation rounding the whole Amerasian basin.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 09, 2018, 12:13:07 AM
Mercator 300m current, oct8 though it's probably easier to see in the salinity/temp animations. I'm not sure how to match the buoy locations to the mercator model.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 09, 2018, 02:19:11 PM
I won't update the buoy data every day, just until things settle down a bit.
ITP110 appears to be recovering from a glitch at day265 or it had a shock event followed by a low salinity area.
ITP109 has a milder event at day275.
I suppose if you were looking for a slow velocity wave there might be something to investigate there. Perhaps it is all glitches.

"The Ice-Tethered Profiler data were collected and made available by the Ice-Tethered Profiler Program (Toole et al., 2011; Krishfield et al., 2008) based at the Woods Hole Oceanographic Institution (http://www.whoi.edu/itp)."
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on October 09, 2018, 07:50:18 PM
I was thinking more of a low velocity but coherent current more direct than the model shows, and thought the eddies would be suppressed that deep, but I guess whichever way the current moves it rotates and bends. There may be no glitches, if the sensor is crossing a deep current or heading in the same direction the rate of change will vary, I'm in no position to judge if that's what's happening.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 10, 2018, 12:52:31 PM
So maybe they tethered itp110 almost directly over a freshwater current heading for the Mclure Strait. A bit deep for that though, isn't it?

Looking less like a glitch today as the temperature  profile at depth is matching salinity on 110.

Can anyone recommend a temp/salinity profile contours tutorial?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 10, 2018, 02:45:56 PM
Not wanting to skip around too much but since waves are in the thread title, here is oct10-19 ecmwf wave forecast from windy.
For a change of model, Hycom sea surface temperature, mar-oct9.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 10, 2018, 11:03:21 PM
Back to ITP110. X marks the spot on the image below where I think ITP110 is today. An estimate based on the latest drift track above. Salinity at 300m there is modelled at ~34.5. The scales are different but ITP110 had simliar 300m salinity until recently.
If it keeps heading towards the Mclure Strait there should be a significant rise.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 11, 2018, 10:17:48 PM
I looked at the [edit] last few data files and I don't think there is a problem with ITP110 (down to 300m). We'll see.  Latest measurements:
ITP110 300m salinity 34.5047 temp 0.1819C (0C at ~285m)
ITP109 300m salinity 34.4592 temp -0.1894C (0C at ~315m)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 12, 2018, 12:21:27 AM
It appears that ITP107 may help....

The Ice-Tethered Profiler data were collected and made available by the Ice-Tethered Profiler Program (Toole et al., 2011; Krishfield et al., 2008) based at the Woods Hole Oceanographic Institution (http://www.whoi.edu/itp).
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on October 12, 2018, 01:00:28 AM
Unicorn, There are six new ITP buoys that are all working. I am interested in the depth of the surface fresh water layer at the center of the Beaufort Gyre. It may be awhile till any of the new buoys get there however. The one profiler ( 108 ) that was working for the 2018 melting season never did join the clockwise spin of the Beaufort gyre and instead made a straight line from launch to the Amundsen Gulf. It's course made me wonder if some of the Beaufort surface fresh water exited with the buoy .
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 12, 2018, 01:15:17 AM
Great, I'll add them to the gif tomorrow
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sleepy on October 12, 2018, 08:29:07 AM
Nice thread., thanks.
New paper here:
Arctic sea ice thickness, volume, and multiyear ice coverage: losses and coupled variability (1958–2018)
http://iopscience.iop.org/article/10.1088/1748-9326/aae3ec (http://iopscience.iop.org/article/10.1088/1748-9326/aae3ec)
Article at NASA:
With Thick Ice Gone, Arctic Sea Ice Changes More Slowly
https://www.jpl.nasa.gov/news/news.php?feature=7258 (https://www.jpl.nasa.gov/news/news.php?feature=7258)

Edit; not sure if this is useful but also adding a pdf by Mikhalewsky from last year and the link to the SCICEX data.
https://www.ldeo.columbia.edu/res/pi/SCICEX/ (https://www.ldeo.columbia.edu/res/pi/SCICEX/)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 12, 2018, 01:07:40 PM
Thanks for those sleepy. Here are the latest data from 6 active ITP's.
Thanks to Woods Hole Oceanographic Institute http://www.whoi.edu/page.do?pid=163197)
edit:@Bruce Steele. What are your rough coords for the centre of the Beaufort Gyre?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on October 12, 2018, 09:04:03 PM
Uniquorn, Generally I look at the BGOS buoys as bounding the gyre. If you look at itp 109 as being the closest you can see it also has the surface fresh water closest to the surface in contrast to the other buoys currently sending data. I would think the buoys closest to the center of the gyre should have the deepest surface fresh water layer. You can check out completed missions to get past data. Itp 85 tracked fairly close to where itp 109 has tracked or itp 78 for a buoy that did a circle around the gyre.
I probably should defer to Fish Out of Water on the drivers of the current status but I wonder about the gyre spinning counterclockwise this fall and the effects of that relaxation event. Fish had this to say over on the freezing season page today

"The problem on the Bering side is the unprecedented heat flux into the Arctic. Warm, moderatly salty Pacific water has flowed into the Arctic then descended to the 30m to 100m level, below the fresh water layer caused by Siberian river influx.

There's a rapidly growing amount of heat in the Pacific water layer above the Atlantic water layer which is shoaling as freshwater is flowing out of the Arctic through the CAA and the Fram strait."

So is the shoaling of the warm Pacific water, evidenced by itp 109 ,displacing the surface water or did the surface water spin out with the relaxation of the clockwise rotation of the gyre ?


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 12, 2018, 10:25:50 PM
Probably a good time to post Mercator 0m salinity, jul2017-oct2018, every 4days. The model does show a slow down in rotation. Not sure about counter clockwise yet.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 13, 2018, 12:37:17 AM
Posting ascat mar-oct, every 3 days just to verify surface movement in the Beaufort. (sorry, no dates on this one)
say goodbye to all that MYI
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on October 13, 2018, 02:04:57 AM
Uniquorn, OK there doesn't look like there was a reversal. Next question , how much evidence do we have that surface fresh water layer has thinned? Was there a relaxation of the gyre and how long would it take for a measurable portion of the surface water to excape its grip . I am hoping this years deployment of ice tethered profilers will show us some more about the surface layer questions closer to the center of the gyre.
 Thanks for the great animations.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 13, 2018, 02:35:31 AM
we have a lot of acorns this year ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on October 13, 2018, 04:01:14 AM
It's the Atlantic water that has been rising up - shoaling, as we have noted, at the 300m level near the continental margin. The Pacific water layer can be inferred on the Beaufort side of the Arctic on Mercator by the 100m layer mapping of salinity. Unfortunately, Mercator isn't particularly useful for looking at temperature anomalies that might be related to the Pacific layer.

I'm making the conclusion on where the incoming Pacific water is going based on what I can see on Mercator & SST maps about the water flowing into the Chukchi and the recent paper that traced the increase in heat content based on tracking water that sank on the margins of the Chukchi sea in recent years. I'm assuming that same thing is happening now as happened in previous years to excess summer water heat in the Chukchi.

Summer like inflow into the Chukchi has lasted longer into fall for the past 2 years. The heat this fall is shocking, but I'm assuming that it's going to have the same fate as heat from previous summers.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on October 13, 2018, 04:21:10 AM
I think that cyclonic conditions around Greenland this past year caused fresh water to flow out of the Arctic ocean at higher than normal rates. The early opening of the passages of the CAA and the strong flow of sea ice through those passages this late summer are additional evidence of a strong fresh water flux through the CAA.

Here's a paper that helps explain my reasoning and if you remember this late spring and early summer there was a highly anomalous cyclonic atmospheric circulation around Greenland.

https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-13-00389.1

Abstract

Decadal changes of the liquid freshwater content in the Arctic Ocean are studied with a suite of forward and adjoint model simulations. Adjoint sensitivities show that freshwater volume changes in the Norwegian Atlantic Current north of the Lofoten basin and a salinity maximum in the Fram Strait and in the Canadian Archipelago lead to an enhanced northward transport of freshwater. The dynamical sensitivities indicate that stronger freshwater export from the Arctic is related to an enhanced cyclonic circulation around Greenland, with an enhanced export through the Canadian Archipelago and a stronger circulation within the Fram Strait. Associated with this circulation around Greenland is a large-scale cyclonic circulation in the Arctic. Cyclonic wind stress anomalies in the Arctic Ocean as well as over the Nordic seas and parts of the subpolar Atlantic are optimal to force the freshwater transport changes.

Results from a simulation over the period 1948–2010 corroborate the result that Arctic freshwater content changes are mainly related to the strength of the circulation around Greenland. Volume transport changes are more important than salinity changes. Freshwater content changes can be explained by wind stress–driven transport variability, with larger export for cyclonic atmospheric forcing. By redistributing freshwater within the Arctic, cyclonic wind stress leads to high sea level in the periphery of the Arctic, and the stronger gradient from the Arctic to the North Atlantic enhances the export through the passages. A second mechanism is the wind-driven Sverdrup circulation, which can be described by Godfrey’s (1989) “island rule” including friction. For this, wind stress in the Arctic is not important.




Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 13, 2018, 12:37:52 PM
It's the Atlantic water that has been rising up - shoaling, as we have noted, at the 300m level near the continental margin. <snippage>
Some evidence of large salinity increase at 300m on today's whoi ITP103 profile. Second animation shows the 6 drift tracks merged and mercator 300m salinity map.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 14, 2018, 02:23:39 PM
Today's itp location and profile contours. Reminded myself that mercator model is 318m (which makes quite a difference on these charts)
Will let them drift a bit before making any comment.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 14, 2018, 02:47:36 PM
Last years whoi itp's for reference. Grey background to aid identification.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 14, 2018, 11:29:30 PM
The Coriolis effect tends to cause water to deflect to the right side of channels and passageways into and out of the Arctic ocean. Thus most water that flows out of the CAA is unlikely to flow back into the Arctic through the Nares strait. That animation does show a surge of fresh water up the Nares strait but most of that fresh water likely came from Greenland meltwater in my opinion. Obviously, with all the complex loops, small gyres and tidal effects some CAA fresh water could spin back into the Nares.
Example of the coriolis effect in the Nares Strait. Ice tends to flow down the west side of the strait into Baffin Bay.
amsr2-uhh, nares strait, sept-oct
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on October 15, 2018, 10:27:37 AM
There are tidal surges up Nares that push a current out into the arctic briefly, usually on the Ellesmere side, so arctic water, they can be exagerated by mslp differences and surface winds. It's just a temporary phenomenon, as far as I can tell, there's a powerful negative pressure in Baffin which I think is caused to a large degree by tidal harmonics. Glimpse (https://puu.sh/Be9ZN/b149103b95.jpg)
 We may yet see a reversal of the gyre, both Atl. and Pac. waters would be more 'comfrotable' with a ccw movement, with so much flow through the CAA a high in Bering and a low by Amundsen may be enough to force the change. How much further would the Atl. penetrate?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 15, 2018, 05:39:09 PM
Hycom salinity 0m, nov2016-oct2018. It looks like clockwise rotation is set to continue.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 17, 2018, 07:37:43 PM
Copied from the freezing thread
Interesting study from MIT shows a change in the rotational speed of the Beaufort Gyre due to loss of ice in that area. This seems to affect many of the parameters associated with ice drift, salinity , AMOC etc.
Perhaps other more learned Forum members might like to discuss the repercussions .....

http://news.mit.edu/2018/arctic-ice-sets-speed-ocean-current-1017
That paper is saying what A-Team and I have been saying for some time. There are a number of papers about the increase in the fresh water content of the Beaufort gyre from 2000 - 2015. We know that the gyre has spun up with the decline of multiyear sea ice and we know why. This paper quantifies it and models it.

What A-Team and I have been saying is that there is now evidence of weakening of the gyre in response to increased storminess over the past several years. The release of fresh water from the gyre is one of the causes of the cold SST anomaly in the Greenland and Labrador seas.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 17, 2018, 10:44:02 PM
Just an ignorant question: Is there any buoy or float in that area that can verify that the anomaly is actually there? I keep wondering at Mercator's animations (and Hycom's) what the actual level of data behind them.
It should be noted that the last 2 or 3days of profile contours can change significantly.

ITP103
I don't understand the datafile yet but based on the profile contour chart 312m salinity has risen from ~34.7 to 34.8. That's yellowish to orange on the mercator map. Reasonable agreement.

ITP104 and 105 appear to be stuck at the moment.

ITP107
Year   Day             dbar   temp      salinity    oxygen
2018  290.02022  312    0.1960   34.6094  265.8341
Today's reading of ~34.6 agrees well with its position on the mercator map. It also had a big dip in salinity as suggested by the model.

ITP109 (no oxygen)
2018  290.02020  312   -0.0324   34.4906
Today's reading of ~34.5 agrees well with the position on the mercator map. I'm not sure it matches up so well with the mercator contours en route.
 
ITP110
2018  290.02069  312    0.2594   34.6187  264.3407
Today's reading of ~34.6 is a bit lower than the mercator map ~34.7 but the salinity changes on route do match up quite well with the map

All in all, I think there is some validity to the mercator model based on the buoy data so far.

active whoi ITP's 103-110, drift tracks and profile contours, oct17
Drift tracks merged with mercator 312m salinity map, oct17. (edited size)

all data available from http://www.whoi.edu/page.do?pid=163197

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 17, 2018, 11:20:41 PM
If they gave an actual link to the paper one of us could probably pull it up. Instead, they give us their science writer's PR and no link to the source.

BINGO! Found it

Googled " Beaufort Gyre Governor " and got - http://oceans.mit.edu/JohnMarshall/wp-content/uploads/2018/02/meneghello2018governor.pdf

I am supposed to be doing my personal admin but.....

Thanks for the link. This is a model study to test the hypothesis that sea ice acts as a governor to the Beaufort gyre. Here's the introductory statement to what they did:

To  explore  the  governor  mechanism  and  test  our  theoretical  model,  we  analyze  the
response of an idealized gyre under two different limit-case scenarios:  i) an ice-driven gyre
(α=1 in equation 1, in which forcing depends purely on gradients ofτ=τi) and

 ii) an ice free, wind-driven gyre (α=0, in which forcing depends purely on gradients of τ=τa).

We conclude with a discussion of the implications of the governor for the Arctic Ocean’s
circulation and its fresh water content.

The implications of this study are quite significant. Without the sea ice governor, the Beaufort gyre will go through sudden expansions and contractions. Large pulses of fresh water will be released to the Labrador sea causing sudden disruptions of the meridional overturning circulation (MOC). This will destabilize NH winter weather patterns causing swings from warm to cold over periods that haven't yet been determined, perhaps decadal or less.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on October 17, 2018, 11:46:42 PM
Quote
All in all, I think there is some validity to the mercator model based on the buoy data so far.
Great analysis, thanks. I was good friends with the camera-based top-measuring O-buoys, but one look at these ITP contours and my eyes glaze over.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 18, 2018, 12:58:27 PM
just deglazing mine now ;)
This weeks ecmwf wave forecast from windy.
Bigger waves maybe not making it through to the Laptev now.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 18, 2018, 10:22:25 PM
Open ocean cooling steadily. Salinity still increasing on Pacific and Atlantic sides.

Mercator 0m temperature and salinity, oct1-17.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Cid_Yama on October 19, 2018, 05:24:17 PM
Arctic ice sets speed limit for major ocean current
Quote
The Beaufort Gyre is an enormous, 600-mile-wide pool of swirling cold, fresh water in the Arctic Ocean, just north of Alaska and Canada. In the winter, this current is covered by a thick cap of ice. Each summer, as the ice melts away, the exposed gyre gathers up sea ice and river runoff, and draws it down to create a huge reservoir of frigid fresh water, equal to the volume of all the Great Lakes combined.

Scientists at MIT have now identified a key mechanism, which they call the "ice-ocean governor," that controls how fast the Beaufort Gyre spins and how much fresh water it stores. In a paper published today in Geophysical Research Letters, the researchers report that the Arctic's ice cover essentially sets a speed limit on the gyre's spin.

In the past two decades, as temperatures have risen globally, the Arctic's summer ice has progressively shrunk in size. The team has observed that, with less ice available to control the Beaufort Gyre's spin, the current has sped up in recent years, gathering up more sea ice and expanding in both volume and depth.

If global temperatures continue to climb, the researchers expect that the mechanism governing the gyre's spin will diminish. With no governor to limit its speed, the researchers say the gyre will likely transition into "a new regime" and eventually spill over, like an overflowing bathtub, releasing huge volumes of cold, fresh water into the North Atlantic, which could affect the global climate and ocean circulation.

"This changing ice cover in the Arctic is changing the system which is driving the Beaufort Gyre, and changing its stability and intensity," says Gianluca Meneghello, a research scientist in MIT's Department of Earth, Atmospheric and Planetary Sciences. "If all this fresh water is released, it will affect the circulation of the Atlantic."

Meneghello is a co-author of the paper, along with John Marshall, the Cecil and Ida Green Professor of Oceanography, Jean-Michel Campin and Edward Doddridge of MIT, and Mary-Louise Timmermans of Yale University.

A "new Arctic ocean"
 
There have been a handful of times in the recorded past when the Beaufort Gyre has spilled over, beginning with the Great Salinity Anomaly in the late 1960s, when the gyre sent a surge of cold, fresh water southward. Fresh water has the potential to dampen the ocean's overturning circulation, affecting surface temperatures and perhaps storminess and climate.

Similar events could transpire if the Arctic ice controlling the Beaufort Gyre's spin continues to recede each year.

"If this ice-ocean governor goes away, then we will end up with basically a new Arctic ocean," Marshall says.
 
"In a warming world"
 
Marshall and Meneghello note that, as Arctic temperatures have risen in the last two decades, and summertime ice has shrunk with each year, the speed of the Beaufort Gyre has increased. Its currents have become more variable and unpredictable, and are only slightly slowed by the return of ice in the winter.

"At some point, if this trend continues, the gyre can't swallow all this fresh water that it's drawing down," Marshall says. Eventually, the levee will likely break and the gyre will burst, releasing hundreds of billions of gallons of cold, fresh water into the North Atlantic.

An increasingly unstable Beaufort Gyre could also disrupt the Arctic's halocline -- the layer of ocean water underlying the gyre's cold freshwater, that insulates it from much deeper, warmer, and saltier water. If the halocline is somehow weakened by a more instable gyre, this could encourage warmer waters to rise up, further melting the Arctic ice.


"This is part of what we're seeing in a warming world," Marshall says. "We know the global mean temperatures are going up, but the Arctic tempertures are going up even more. So the Arctic is very vulnerable to climate change. And we're going to live through a period where the governor goes away, essentially."
link (https://www.eurekalert.org/pub_releases/2018-10/miot-ais101718.php)

The research paper (https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2018GL080171?referrer_access_token=rRLNlYJSW-oXwqMzQfGOGsOuACxIJX3yJRZRu4P4ervn61VIykWY5YWIytNp6u1vnBrwhD7pPGe-9rb1xpZHbqzR9Y1mNbjHw_NG4RlgTm-wCZn94UviiAQJMP4hFGJK)

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: RoxTheGeologist on October 19, 2018, 07:47:38 PM
Open ocean cooling steadily. Salinity still increasing on Pacific and Atlantic sides.

Mercator 0m temperature and salinity, oct1-17.

Surface cooling causing mixing and exasperating lack of input of freshwater from melt and rivers?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 19, 2018, 10:39:21 PM
yikes, will have to think about that one
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on October 19, 2018, 10:59:45 PM
Rox, I'm seeing that differently, the flash freeze by the 'blob' caused by currents from Amundsen bringing and mixing the freshwater from Mackenzie with bottom melt, waves bringing lightweight ice in windrows from the fraying ice edge, with arid -3C air passing over, a little evaporation...
The siberian river waters look like they're dropping into the deep caused by the suction of the Pacific waters leading the way, when they hit bottom they're mixing with Atl. waters which are here being forced north, the turbulence/vortices may be mixing or refining the various sources qualities/energies.
Plus the lows in Labrador have created an anomolous 'vacuum' in Baffin sucking an increased flow through Nares/Lancaster.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 20, 2018, 10:02:50 PM
The explanation for the Beaufort flash freeze looks plausible. I'm not sure about fresh water being sucked down with Pacific water. Isn't surface mixing more likely?

The Bering Strait didn't have ice cover till mid Jan this year. It's possible that, with higher SST, it will be even later in 2019. Until then, warmer higher salinity water will likely be flowing into the Chukchi.

On the Atlantic side, a rather fragile ice front is approaching Severnay Zemlya. It is already reducing wave height and I had assumed that it would largely arrest the flow of higher salinity surface water into the Laptev, but looking a Mercator last year, it just carries on (at 0m)under the ice until the melting season starts. So it needs to be 'a bit' colder to freeze and may have less time to extrude the brine.

Anyway, enough of 0m. Here is an update of Mercator 318m salinity sep15-oct19
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on October 21, 2018, 11:45:29 AM
It[Siberian river water] does mix to the west of Wrangel but just to the east the shallow basin is occupied by Pac. waters, and further out the gyre, the Pac. water follows the contours down, none of the fresh water gets past unmixed and seems to accelerate towards the drop. http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20180909/20181020/2/1
(https://puu.sh/BOx4T/c3e3543e4f.jpg)
Much of our attention is focussed on the ice through Fram and the flow through Nares, I'm thinking the greatest change may have been the amount of freshwater flow out of Lancaster sound. For the Atl. water to penetrate so far and for so long the same amount has to exit.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 21, 2018, 10:50:40 PM
Looking at Mercator model 0m and 30m salinity, oct10-20 there is a narrow flow of fresher water heading south along the Russian coast and a pulse at 34m that makes it to the bering strait. Possibly the first time it has made it that far this year.
Agreed, a flow heading northwards from Wrangel Island is also visible that mixes with the incoming Bering water.
Possibly they make it to 300m, there is a rim of lower salinity around the drop.(see 300m upthread)

Where can I find that bathymetry map?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 21, 2018, 11:01:25 PM
To my untrained eyes, it looks like they carry on north at 92m. But this is all a model ;)
edit:Lancaster Sound, good point, but how to quantify?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Niall Dollard on October 21, 2018, 11:30:25 PM
Brigantine posted this link to a detailed bathymetry data viewer :

I'll just leave this bathymetry map (https://maps.ngdc.noaa.gov/viewers/bathymetry/) here.

(Note in the right hand sidebar the arctic map option, and the top right options drop menu the regional bathymetric contours. Also turn multibeam bathymetric surveys off.)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: El Cid on October 22, 2018, 08:54:01 AM
Has anyone got a good chart that compares this years salinity profile to eg 5 or 10 yrs ago?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 22, 2018, 10:24:22 PM
Not saying it's good but here is hycom sea surface salinity oct22, 2014 and 2018.
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

copernicus has SSS going back to 1991 in netcdf, free registration
http://marine.copernicus.eu/services-portfolio/access-to-products/
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 22, 2018, 10:39:28 PM
Bruce Steele will be pleased that all 6 buoys look like they are following the gyre current.
ITP 105, 107 and 110 all show higher salinity at times, in some agreement with the mercator model but, due to the gyre, they may all miss the highest salinity area.
Unfortunately, I don't think there are any buoys in the Chukchi to verify increasing salinity at 300m there (see above)

Today's ITP locations and profile contours.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: El Cid on October 23, 2018, 07:36:44 AM
Thank you uniquorn!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 23, 2018, 09:39:06 PM
Copied this from AbruptSLR thread.  (edit - my brown and bold)

Meneghello G. , J. Marshall, M.-L. Timmermans and J. Scott (2018). Observations of seasonal upwelling and downwelling in the Beaufort Sea mediated by sea ice. J. Phys. Oceanogr., 48, 795–805. doi:10.1175/JPO-D-17-0188.1

https://journals.ametsoc.org/doi/10.1175/JPO-D-17-0188.1 paywalled :(

Abstract: "We present observational estimates of Ekman pumping in the Beaufort Gyre region. Averaged over the Canada Basin, the results show a 2003–14 average of 2.3 m yr−1 downward with strong seasonal and interannual variability superimposed: monthly and yearly means range from 30 m yr−1 downward to 10 m yr−1 upward. A clear, seasonal cycle is evident with intense downwelling in autumn and upwelling during the winter months, despite the wind forcing being downwelling favorable year-round. Wintertime upwelling is associated with friction between the large-scale Beaufort Gyre ocean circulation and the surface ice pack and contrasts with previous estimates of yearlong downwelling; as a consequence, the yearly cumulative Ekman pumping over the gyre is significantly reduced. The spatial distribution of Ekman pumping is also modified, with the Beaufort Gyre region showing alternating, moderate upwelling and downwelling, while a more intense, yearlong downwelling averaging 18 m yr−1 is identified in the northern Chukchi Sea region. Implications of the results for understanding Arctic Ocean dynamics and change are discussed."
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on October 23, 2018, 10:52:36 PM
Uniquorn, I found a compendium of Beaufort gyre fresh water content on a data page for the BGOS buoys. It shows a buildup of surface fresh water between 2013 and 2017.  It will be another year until the 2018 data gets incorporated , I wonder if some of the 2017 surface fresh water exited via the Amundsen in 2018 and whether it will show up as a surface fresh water decrease in the data we get to see next fall.
 Also interesting to see the fresh water decrease from 2012 to 2013.

http://www.whoi.edu/page.do?pid=161756

Also nice discussion piece on Beaufort fresh water

http://www.whoi.edu/page.do?pid=66597
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: RoxTheGeologist on October 24, 2018, 02:32:47 PM
....while a more intense, yearlong downwelling averaging 18 m yr−1 is identified in the northern Chukchi Sea region[/b]...."

Anybody with access care to enlighten us poor souls on the other side of the wall? Is this where dense salty water meets the continental slope of the Canadian Basin?

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 24, 2018, 09:37:04 PM
Thanks Bruce Steele. Gridded data, my next learning curve :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sleepy on October 25, 2018, 04:43:53 AM
Attaching the early online release of Meneghello.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 25, 2018, 02:50:39 PM
upwelling images from the early online release of Meneghello
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 27, 2018, 07:30:23 PM
The halocline must struggle to survive along the atlantic ice front. Svalbard, FJL and SZ have, until recently, been a helpful line of defence, enabling coastal freezing and protecting land fast ice from storms, providing calmer waters that would encourage halocline development.

Looking at jaxa rgb, mar-oct, on the atlantic side:
Svalbard had largely wind driven ice on the southern side. Open water to the north all this year.
Franz Josef Land had wind driven ice and open water(varying sides) from mar16.
Severnaya Zemlya had open water on the eastern side from jun7.

I expect the halocline is disturbed to varying extents beneath mobile ice, depending on the distance from the ice front. Everything west of SZ will probably continue to be very disturbed. Thin salty ice may not be much help.
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on October 27, 2018, 08:53:54 PM
nice animation.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 28, 2018, 07:14:58 PM
Unable to get 3d mode on windy recently so here is a 2d version of ecmwf wave forecast, oct28-nov6.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 29, 2018, 11:29:39 PM
Strong south easterlies sent most of the buoys (and the ice) back the way they came.
whoi itp103-110 locations and profile contours, oct29

note: the latest readings to the right of the profile contours often change after a few days, probably due to algorithm or human intervention. Raw data is available from www.whoi.edu/page.do?pid=163197
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on October 30, 2018, 12:22:50 AM
Uniquorn, Three of the ITP buoys 107, 109 and 110 show a layer of > -.4 C Pacific Summer Water that is 50 meters thick. I have gone back though the completed missions looking for something similar but it looks pretty unusual .

As uniquorn pointed out , I missed the minus sign.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 30, 2018, 01:50:25 AM
Yes. Possibly unusual. Some recent profiles have a similar layer but not so thick. Here are relevant Beaufort buoy locprofs from 80-108 (2015-18). Will take a look at older ones tomorrow.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 30, 2018, 10:29:32 PM
Uniquorn, Three of the ITP buoys 107, 109 and 110 show a layer of > .4 C Pacific Summer Water that is 50 meters thick. I have gone back though the completed missions looking for something similar but it looks pretty unusual .
Looking at the grddata files, not so much of the orange band is >.4C, example of day300. It may still be significant though.
dbar~= depth in m
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Red on October 31, 2018, 08:47:26 PM
Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition.
Very interesting but way over my pay grade.

https://www.nature.com/articles/s41586-018-0651-8.epdf?referrer_access_token=n8le7-cNM4FyKQmfBHPF1dRgN0jAjWel9jnR3ZoTv0PPM6F5Tw--xUcDaVyo5KYP7_G9gTDd9jkXQCGLmYVcdiHz9wkwN0E6N2nDZlq4WDQgItGi5ylVScf0yzGnaEVfvjiMb4AD29fhh3xQR3z_DrC_cMrTVL7ZhdR6IhWWEdbaBw61pmJWfJX3nlJ6qnYm0eEGF290YDw0L29Qu1D0Zo3ti9EtUV0eTqh8Y9w5-oUx2QwN2d9ZfvrbV8VI76Jac_wGy8vU0HDJC8kZsxCODV2aVpQq0121i0ZxM9IekpFGQF_rkVmbw0g8I4hVq8LyScrOgOKTXDVHHUeUBJuft2b1dNC8ezHr4dPD3Biz3roLxxVBtZ8VpLaIeiCuYRUYZF7A3wfP2jIvDwVvQWTRXYcc11VeMhxlE-R3GeWQulM%3D&tracking_referrer=www.washingtonpost.com
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 01, 2018, 07:53:43 PM
Uniquorn, Three of the ITP buoys 107, 109 and 110 show a layer of > .4 C Pacific Summer Water that is 50 meters thick. I have gone back though the completed missions looking for something similar but it looks pretty unusual .
Maybe the scale is too small to see the minus sign, it's -0.4
It's still a thick layer though. How does that form?
1. Long period of overturning during the summer? - Beaufort weather might have been too stormy for that.
2. Incoming warm higher saline flow from Bering?
3. Centripetal effect of the gyre? 107 and 110 look like they drifted out and back into the thicker layer. 109 is more central and stays in it.

edit:updated image again, temps not much use without salinity
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sterks on November 01, 2018, 08:45:26 PM
Uniquorn, Three of the ITP buoys 107, 109 and 110 show a layer of > .4 C Pacific Summer Water that is 50 meters thick. I have gone back though the completed missions looking for something similar but it looks pretty unusual .
Let me know if I am wrong. That excess of heat in the Pacific side, whether 30 m or 50 m thick, is locked there by stratification and doesn't reach the surface except in unprecedented events (GAC?).
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 01, 2018, 10:16:42 PM
Uniquorn, Three of the ITP buoys 107, 109 and 110 show a layer of > .4 C Pacific Summer Water that is 50 meters thick. I have gone back though the completed missions looking for something similar but it looks pretty unusual .
Let me know if I am wrong. That excess of heat in the Pacific side, whether 30 m or 50 m thick, is locked there by stratification and doesn't reach the surface except in unprecedented events (GAC?).
Not wrong.
The thread documents that, according to buoy data, the a warm layer near the gyre appears to be thicker than previous years. The mercator model shows some flow of warmer water from the bering/ chukchi at depth. Is there another model that shows more than 0m data?

edit: wanted to keep this post from AbruptSLR alive https://forum.arctic-sea-ice.net/index.php/topic,2391.msg170451.html#msg170451

with this quote:
The one consideration that you are ignoring is that per the research that I reference in Reply #5, the relatively freshwater layer immediately above the deeper warm layer of water, is unstable.  So it is not that the deeper and denser warm water will magically float up through less dense cooler water, but rather that the upper cooler/fresher lay may well some day flow laterally away (into the North Atlantic) which would then leave the warm water closer to the surface.

mercator model, temperature at 0m, 34m, 92m, oct31
edit: Mercator shows a lot more detail when not using the fixed scale(colorbar). Changed the animation to show salinity and temperature for nov2, 0m-300m
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 06, 2018, 09:18:35 PM
cross posting for easy access

There may be some evidence of persistent upwelling north of Svalbard. The uni-hamburg amsr2 animation below (oct1-nov5) has been heavily contrasted on the right hand side to bring out the lower concentration areas (edit:some of the transient blue is weather). The area with persistent low concentration, even as the ice moves across it, is marked on the left.

The polarview image (nov5) shows the rough location of the possible upwelling and what may be a recently melted area that is heading towards the Fram Strait.
This may not be a new feature, perhaps the ice is now thin enough to reveal it.

The mercator ocean animation shows salinity and temperature at 34m and 0m (the scale is cut off for better clarity). Basic internet research suggests there is an eddy from 0-30m depth, possibly caused by the interaction of the cold and warm currents in that area. Initial suggestion was upwelling, but it could downwelling, cooling, then going south. The model has the eddy closer to the Fram Strait. There may be more that don't show.
the last 0m frame and all temp34m dates were misplaced during the making of this animation, none of them were harmed. edit:A downloaded version is much clearer

The final animation uses amsr2-uhh again, with high contrast on the right, focusing on the area close to the eddy from mar21-nov5, looking for persistance. It appears to be visible from ice movement from the beginning of August. Before that is unclear.


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on November 06, 2018, 09:30:59 PM
Detail from (https://maps.ngdc.noaa.gov/viewers/bathymetry/)

(https://puu.sh/BXqlV/6dfeabf8e8.jpg[url][/url])
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 06, 2018, 10:17:56 PM
Niagara Falls in slow motion then.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on November 07, 2018, 12:53:39 AM
My guess would be a deep current flowing towards Fram meeting the incoming current merging and being forced to climb the peninsular[?]. With 5-700m to penetrate it's hard to be sure where the disturbance originates. That it reaches the surface suggests that a vortice is resisting approaching the axis of rotation. Any sign of rotation?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sleepy on November 07, 2018, 04:57:26 AM
Thank you for diving into that. If I remember correctly, that feature has been noticed on this forum in previous years as well, at least in 2015 and 2016.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 07, 2018, 02:41:32 PM
So it is persistent or seasonal then (edit: or occasional). I haven't read everything that far back.(yet)

Always cloudy there in worldview bt15 recently and difficult to spot rotation on polarview.

Overnight, I was wondering if it was more of a subduction whirlpool (does that exist?) going down the valley, but looking at it again, that's too near to Svalbard.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 07, 2018, 06:50:30 PM
I went back to 2013 searching for Svalbard upwelling on asif. There are many comments about the hotspot to the west and the atlantic current to the north. Also another possible eddy event closer to FJL. No confirmation of this possibly persistent low concentration area yet. Maybe I will trawl through all Sleepy's comments....lot's of good stuff though:

https://forum.arctic-sea-ice.net/index.php/topic,1377.msg68881.html#msg68881
https://forum.arctic-sea-ice.net/index.php/topic,1377.msg68886.html#msg68886
https://forum.arctic-sea-ice.net/index.php/topic,1504.msg74014.html#msg74014
https://forum.arctic-sea-ice.net/index.php/topic,1504.msg74444.html#msg74444

http://onlinelibrary.wiley.com/doi/10.1002/2016GL068323/full free :)
this extract may be relevant to the north of Svalbard under the present conditions:
Farther west along the recirculation pathway, however, salinity dominates the buoyancy, eventually forcing the westward flowing AW to subduct underneath the PW. While such vertical adjustment is difficult to obtain by the nearly nondivergent geostrophic flow, mesoscale eddies can efficiently mediate vertical temperature and buoyancy fluxes. The time‐mean depth‐integrated vertical eddy temperature flux in Figure 3d shows that eddy processes likely play an important role for this subduction of AW. Large upward eddy temperature fluxes along the WSC (red shading in Figure 3d), i.e., in the temperature‐stratified east, imply a release of available potential energy as would be expected from baroclinic instability. Along the frontal zone itself, the vertical eddy fluxes are near zero, but in a large region west of the Molloy Hole they are distinctively negative (blue shading). This salt‐stratified region is also associated with downward salt fluxes and therefore upward buoyancy fluxes (both not shown). So vertical eddy fluxes release available potential energy there too, and the subduction of AW underneath PW should be understood as a natural consequence of this ubiquitous tendency. Mesoscale dynamics, apparently, are therefore instrumental to both lateral and vertical advection of AW in the Fram Strait.


https://forum.arctic-sea-ice.net/index.php/topic,1344.msg59455.html#msg59455
extracts from A-Team that may be relevant:
Another area with a strong seasonal variation is within and to the north of Fram Strait. The Ekman transport in this region is typically westward. It becomes the strongest in the fall and winter just like in the Beaufort Sea. This westward Ekman flow is due to the strong southward ice transport directed toward the Nordic Seas and through Fram Strait. Upwelling and downwelling field are induced by the divergence and convergence of the Ekman transport.......
...There is a strong westward Ekman transport from Svalbard toward Greenland between October and April. This transport is forced mainly by the strong southward sea ice motion associated with the Arctic sea ice export to the Nordic Seas. Consequently, upwelling dominates the eastern Fram Strait while downwelling persists off the Greenland’s coast (Fig. 10). This contrast becomes the most striking in the winter months when the southward ice transport is the largest.

arcticsss_nowcast_anim30d-posted-20131009-by-Laurent:
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on November 07, 2018, 07:40:21 PM
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL068323
animation from the link illustrates/models the eddies
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 07, 2018, 09:32:33 PM
Nice. I couldn't see the link till replying so reposting
https://tinyurl.com/y9r5kgnn

So possibly persistent since at least 2009. Two examples below.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on November 08, 2018, 01:18:50 AM
Thanks for that
Dunno why it didn't show up seemed ok on preview, it did adjust my guess, now I'm thinking that either of the deep currents flowing north could have been forced to the surface the one circling north of the plateau more probable, forced by a general movement of arctic waters towards Fram.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sleepy on November 08, 2018, 07:23:26 AM
Wonderful, I also missed that AVI. Hope you don't mind me adding a smaller MP4 here.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on November 08, 2018, 10:44:18 AM
Looking at 68^ there's chaos in the gyre around June/July, due to the arrangement of highs/lows In Bering and near Banks Is.?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 08, 2018, 10:33:57 PM
That reminds me, haven't posted buoy data for a while. Not much movement at the moment.

Also today's wave forecast from windy, nov8-16

@Sleepy, you are very welcome
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 10, 2018, 02:55:52 PM
Looking at 68^ there's chaos in the gyre around June/July, due to the arrangement of highs/lows In Bering and near Banks Is.?
Quite a push from the Amundson to the Mclure recently
Ascat, oct18-nov9, raw and enhanced.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 13, 2018, 12:02:31 PM
Some clearer weather above the north of Svalbard possible upwelling area today, centre of image.
Worldview, brightness temperature, band15, night, nov13. Two different palettes.
The South of Svalbard shows up clearly to the lower right.

https://tinyurl.com/yajufp5j
The link also shows the more visible hotspot close to the Greenland coast on the 80N line.
Worldview, Greenland sea 80N, brightness temperature, band15, night, nov12-13.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on November 13, 2018, 02:31:22 PM
Beaufort 92^ there was a build up of pressure over the CAA of about 30hpa so some pressure forcing water back to Beaufort, but the rest is so chaotic it's hard to call.
The hot spot by 80N captures vortices on the animation just above at 89^[added]
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 13, 2018, 07:43:11 PM
From the ice movement it looks like clockwise Gyre continues, but the buoys aren't playing ball.
whoi-itp103-110 locations, up to nov13.

Greenland 80N hotspot, going back to oct27 on clear days. Rotation is probably accentuated by current flowing round Greenland. Looks like a distant black hole in red ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on November 14, 2018, 03:34:13 AM
Greenland 80N hotspot, going back to oct27 on clear days. Rotation is probably accentuated by current flowing round Greenland. Looks like a distant black hole in red ;)
Maybe it's a smudge on the satellite's windshield?  ???
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 15, 2018, 06:58:08 PM
Fram strait, amsr2-uhh and mercator 0m salinity, aug24-nov14.
edit: added amsr2 overlaid onto mercator 0m salinity oct1-nov16
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 19, 2018, 12:02:31 PM
update on mercator 300m salinity sep1-nov18(the reason this thread started...)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 22, 2018, 06:33:27 PM
whoi itp buoys 103-105 are heading east. 107 and 109 are heading west, back towards the gyre. 110 not moving much at the moment.

Today's data from itp109 from 50-100m: (dbar ~ depth)
year    day            dbar   temp(C)  salinity
2018  326.03184   50   -0.3486   30.1677
2018  326.03176   52   -0.2867   30.3608
2018  326.03168   54   -0.1823   30.5148
2018  326.03159   56   -0.1005   30.6669
2018  326.03149   58    0.0696   30.8080
2018  326.03140   60    0.1213   30.9207
2018  326.03132   62    0.1329   31.0197
2018  326.03124   64    0.1086   31.1059
2018  326.03115   66    0.0893   31.1797
2018  326.03105   68    0.0834   31.2508
2018  326.03097   70    0.0754   31.3069
2018  326.03089   72    0.0934   31.3560
2018  326.03080   74    0.1537   31.4148
2018  326.03071   76    0.1713   31.4658
2018  326.03061   78    0.1469   31.5056
2018  326.03053   80    0.2107   31.5394
2018  326.03045   82    0.2617   31.5815
2018  326.03036   84    0.2818   31.6089
2018  326.03027   86    0.2721   31.6315
2018  326.03019   88    0.2270   31.6617
2018  326.03010   90    0.1654   31.6746
2018  326.03001   92    0.1934   31.7077
2018  326.02992   94    0.1781   31.7437
2018  326.02983   96    0.0371   31.7894
2018  326.02975   98    0.0242   31.8080
2018  326.02966  100    0.0679   31.8371
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 23, 2018, 07:25:03 PM
A very good view of the eddy north of Svalbard yesterday on polarview. Definitely some rotation there.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 26, 2018, 10:24:00 PM
Quite a storm brewing on the atlantic side this week.
ecmwf wave forecast from windy, nov27-dec5
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 26, 2018, 10:44:46 PM
Forgot about ice surface temperature.
DMI polarportal, sep14-nov25
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 01, 2018, 06:19:04 PM
Update on the whoi buoys ITP103-110. Their drift track has been more in line with the annual ice drift recently. ITP107 is showing a deeper lower salinity layer as it drifts closer to the gyre. ITP109 is also starting to show a change in profile. Im not sure how to read ITP110.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on December 02, 2018, 06:17:10 PM
Quite a storm brewing on the atlantic side this week.
ecmwf wave forecast from windy, nov27-dec5

Those waves have to wreak havoc on the ice in the Greenland Sea. Especially with sea surface temperatures between 0C and -1.5C lurking nearby.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 03, 2018, 10:30:30 PM
More stormy weather is forecast. I'll revisit this one in a few days.
windy-wam-dec3-forecast-for-dec12, atlantic side.

A comparison of mercator temperature at 0m and 34m depth with JAXA RGB from nov1-dec2 in the Chukchi sea. While the JAXA images that I can easily download are smaller (lower resolution) than amsr2 products they do give a better representation of differing ice types.
When the newer thin ice in the Beaufort meets the eddies on the edge of the gyre the interaction can be seen from ~10-17nov. After that, the thicker ice (in blue) is not so responsive and has picked up a lot of momentum from the continuous 25-40km/h winds over the last week.
Chukchi and Beaufort, Mercator temperature 0m and 34m, jaxa rgb, nov1-dec2

edit:added mercator temperature scales
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on December 04, 2018, 01:56:47 AM
Superb graphics/animations, thanks uniquorn.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 08, 2018, 01:56:59 PM
Worldview, viirs, bt15day doing a great job yesterday in relatively clear weather with a cyclone over the Beaufort gyre (click on the image for full size). Ice lifting off the CAA tending to confirm the mercator model indicating upwelling east and west of the Mclure strait.
Mercator, CAA, 0m and 30m salinity, nov1-dec7.
edit:added salinity scales. (some of the 0m salinity increase should be brine exclusion from freezing ice, but probably not in the Amundsen gulf or along the CAA coast)

worldview link: https://tinyurl.com/yaszxycm

edit2: Added ascat to the salinity animation.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 09, 2018, 04:19:26 PM
Ice near the Mclure Strait rotating anticlockwise during the passage of the last cyclone. edit:Probably temporary.
Worldview, viirs bt15n, dec7-9  https://tinyurl.com/y8qnzkyr
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 10, 2018, 04:45:14 PM
Update on Mercator 0m salinity model showing an atlantic push eastward during the recent stormy weather, possibly causing upwelling on the southern Kara sea coast.
The model also indicating upwelling on the CAA/Beaufort and Chukchi coast. I don't know if the increase in salinity along the CAA is due to brine exclusion or upwelling. Wind driven lift off from the coast is visible on Worldview, but it's been very cold so it's likely the fast ice has been weakened from below. Comments very welcome.
Mercator 0m salinity, nov20-dec9 (scale same as above)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 11, 2018, 06:34:05 PM
The ecmwf wave forecast on dec3 wasn't too bad that far out, though there are pretty large waves most days at the moment. Barents/Kara getting a battering tomorrow but not the CAB.
windy ecmwf wam dec12

edit:
Polarview image yesterday of lower concentration ice north of FJL. Mercator 0m salinity and amsr2-uhh ice concentration inset.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 13, 2018, 10:36:22 PM
Thanks to Brigantine for the heads up on the ARGO float 3902910 currently north of FJL.
The first image shows the drift trajectory and the cycle (report) number. The projection could be better for the arctic but Svalbard is clearly identifiable centre left, FJL under the 80N text.

The animation shows temperature and salinity charts for cycle 65,70,73 and 83-87 (latest). From my limited understanding of the charts, this float appears to have drifted along the ice front in the warm current at depth, surfacing sometimes into cold meltwater, other times into the warm current.
2 days ago SST was 2.5C salinity34.85, today -1.6C salinity 34.15

http://www.argo.ucsd.edu/How_Argo_floats.html
Quote
Argo is an international collaboration that collects high-quality temperature and salinity profiles from the upper 2000m of the ice-free global ocean and currents from intermediate depths. The data come from battery-powered autonomous floats that spend most of their life drifting at depth where they are stabilised by being neutrally buoyant at the "parking depth" pressure by having a density equal to the ambient pressure and a compressibility that is less than that of sea water. At present there are several models of profiling float used in Argo. All work in a similar fashion but differ somewhat in their design characteristics. At typically 10-day intervals, the floats pump fluid into an external bladder and rise to the surface over about 6 hours while measuring temperature and salinity. Satellites or GPS determine the position of the floats when they surface, and the floats transmit their data to the satellites. The bladder then deflates and the float returns to its original density and sinks to drift until the cycle is repeated. Floats are designed to make about 150 such cycles.

data here http://www.argodatamgt.org/Access-to-data/Description-of-all-floats2
choose 3901910

"These data were collected and made freely available by the Coriolis project and programmes that contribute to it (http://www.coriolis.eu.org)."
edit: slowed the gif a bit
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 16, 2018, 12:53:29 PM
An amateur attempt to match argo float 3901910 to amsr2 to see how close to the ice edge it travelled, aug18-dec14. It reported weekly until nov30 and has reporting daily since. Report (cycle) numbers are overlayed onto Greenland, bottom left.
edit:added temp labels

Approximate data based on eyeballing the attached charts is in text below. Timing the temp/salinity data to the animation makes the gif too large. Easiest to download both gifs and step them manually for analysis. (or even better, advice from someone with netcdf skills pls)

The main observation for ice watchers is that the warm current alongside the ice front is ~2.5C at surface recently.

cycle   lat              long          temp C    sal      date
60   80.06547      5.16783      2.75      32.4      0818
61   80.20849      5.23104      5      34.45   0825
62   80.38986      4.78623      2.6      33.65   0901
63   80.48555      6.0284      4.5      34.42   0908
64   80.49247      6.82373      3.8      34.1      0915
65   80.58095      7.16061      4.3      34.1      0922
66   80.44863      8.30625      3.8      34.4      0929
67   80.43952      9.16231      4      34.75   1006
68   80.37718      7.56771      1.5      34.4      1013
69   80.51731      11.28802      0.3      34.1      1020
70   80.84061      14.77375      3      34.75   1027
71   80.85687      16.35878      1.5      34.6      1103
72   81.43671      17.30993      1.6      34.64   1110
73   81.56787      21.71607      -1.2      34.15   1117
74   81.61883      26.34895      -0.7      34.35   1124
75   81.62392      31.29192      -1.5      34.26   1201
76   81.82774      34.03102      -1.1      34.32   1202
77   82.01424      35.80637      -1.6      34.26   1203
78   82.1778      38.04842      2.5      34.82   1204
79   82.28333      39.82095      -1.6      34.23   1205
80   82.29029      39.77042      2.3      34.77   1206
81   82.28489      39.64985      1.8      34.74   1207
82   82.29791      39.56938      2.7      34.86   1208
83   82.25532      39.58456      0.8      34.61   1209
84   82.22805      39.50098      2.7      34.86   1210
85   82.20667      39.35864      2.5      34.86   1211
86   82.21352      39.10944      1.2      34.45   1212
87   82.21687      39.05996      -1.2      34.29   1213
88   82.21415      39.16856      0      34.49      1214

data here http://www.argodatamgt.org/Access-to-data/Description-of-all-floats2
choose 3901910
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 18, 2018, 12:05:10 PM
The argo float must have gone back to a weekly cycle hopefully. Nothing new since 14th.
It should be down there somewhere.
Worldview, viirs, bt15n, dec18 with amsr2-uhh, dec17 inset. North of FJL, more choppy weather coming up.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Brigantine on December 19, 2018, 02:35:24 AM
If ARGO floats suspect sea ice, they won't surface & transmit the new profile. They just save the data and transmit it next time.

Also I don't know how long the batteries will last with no sunlight.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 20, 2018, 11:12:34 PM
Thank you Brigantine.
Update on the whoi ITP buoys. ITP103-5 not drifting much. ITP107 and 109 reporting very low salinity down to ~50m nearer the gyre and 109 still reporting the thick layer of warmer water from ~50-100m with 107 and 110 possibly indicating the boundary of that layer. (will have to look more closely at the data sometime to show that)
Looking at the path of ITP109 compared to mercator model 92m temperature suggests the warm layer is from the Pacific.

whoi ITP103-110, dec20
mercator model 92m temperature, oct1-dec20 edit: should be rotated to match whoi map
mercator model 92m scale
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 21, 2018, 12:28:44 PM
Using mercator 30m salinity here to show the Atlantic current in the Kara Sea. Note the old ice dipping north west of SZ. Didn't really find what I was looking for but posting it anyway for background info.
ascat, smos uni-bremen, mercator 30m salinity, oct17-dec20
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on December 21, 2018, 02:58:24 PM
I took a closer look wanting to see what was happening in the strait at the southern end, I was actually struck by the vorticity north of FJL. http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20181101/20181220/2/2
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 28, 2018, 12:42:13 PM
Update on the persistent low concentration area north of Svalbard.
amsr2-uhh, aug1-dec28, contrast enhanced on rhs.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 28, 2018, 11:02:24 PM
A closer look using worldview, viirs, bt15n, dec23-28.
Low concentration area in the centre, Svalbard far right. Winds are forecast from the west for a few more days so the ice front may reach across the warm current to Svalbard again this year.  The cloud streets thickening up with the increasing temperature difference perhaps.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 30, 2018, 05:56:16 PM
Laptev Sea, amsr2-uhh default and high contrast, oct23-dec29.
Using Mercator 34m salinity here to compare with the underlying current from the atlantic.
salinity scale same as above
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 01, 2019, 06:52:31 PM
It's been a quiet couple of months on the north Greenland coast compared to the last 4 years. Here we are looking for signs of upwelling by increasing contrast to highlight low concentration on amsr2-uhh. Wind driven 'lift off' of ice from the coast is apparent in 2014, 2016 and 2017 but no conclusive evidence of increased upwelling this year.
amsr2-uhh, nov11-dec31, 2014-2018.
days are not quite synchronised due to missing some missing data

edit: Today's worldview image of nth greenland for comparison https://tinyurl.com/ydxhk7sc
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 05, 2019, 04:31:03 PM
Polarview image north west of Svalbard jan5 showing some of the area of warm atlantic water upwelling and what may be evidence of surface currents.

Nullschool version of surface currents jan5.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 06, 2019, 10:53:37 AM
Update on the whoi ITP buoys. http://www.whoi.edu/page.do?pid=163197
ITP103 showing a steady increase in salinity at depth
ITP104 showing a steady increase in salinity at depth (recent data may smooth out)
ITP105 no profile since jan2. Dec31 profile showed a lesser increase in salinity at depth
ITP107 decrease in salinity to ~50m confirming gyre
ITP109 decrease in salinity to ~50m confirming gyre. 50m-100m warm layer
ITP110 confirming 50m-100m warm layer

edit:no further reports from the argo float yet
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 09, 2019, 11:32:50 AM
Atlantic current beneath the ice on it's way to the Laptev.
Worldview, viirs,bt15,night,jan7-9.
Mercator 34m salinity, jan7

edit: polarview image, jan11 for future reference.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 15, 2019, 12:58:58 PM
The warm current north of Svalbard dominates the ice on the atlantic front despite the cold winds from the SSW. Cloud streams highlight the temperature difference (estimates: air ~-30C, water ~2C) and wind direction. Acceleration of ice towards the Fram Strait opening up the already numerous fractures all the way to the Lincoln sea.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 17, 2019, 12:57:12 PM
Using mercator 0m salinity compared with amsr2-uhh sea ice concentration here to show possible upwelling of warmer water along the canada/alaska coast. Nov17-jan16
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 18, 2019, 04:08:18 PM
Update on DMI polar portal ice surface temperature, nov1-jan16.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 18, 2019, 05:07:33 PM
Update on the whoi ITP buoys. http://www.whoi.edu/page.do?pid=163197
ITP103 still showing an increase in salinity at depth
ITP104 little change
ITP105 is reporting again :)  The data may need smoothing.
Both 104 and 105, most northerly, are drifting  further north against the annual drift.
ITP107 decrease in salinity to >50m confirming gyre
ITP109 decrease in salinity to ~50m confirming gyre. 50m-100m warm layer
ITP110 confirming 50m-100m warm layer

argo float 3901910 state is inactive  :(
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 23, 2019, 09:57:47 PM
quick update on whoi itp107 which may have reached the outer extent of the gyre or some other event.
Sharp increase in salinity close to surface.
Not sure about the rest till it settles down.
click for full size
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 23, 2019, 11:15:13 PM
Adding my theory that belongs to me about the Lincoln sea here, updated to jan23. (but it could be the super blood wolf full moon)
Worldview, viirs, bt15n, jan14-23 with NOAA bathymetry map.
will it go beyond the channel?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 24, 2019, 12:41:25 PM
Using mercator salinity at 0m and 30m here to show current as the temperature gradient isn't enough to give much detail. Atlantic water flows south along the Lomonosov Ridge line and then has to circumvent Greenland.
The Mercator model appears to be somewhat validated by the recent ice movement in the Lincoln sea. Note the increase in salinity (and possibly temperature) entering and exiting the Nares Strait, probably from deeper water.
The indications are that warmer saltier water, some of it from much deeper than 30m, flowing into the shallower Lincoln Sea is weakening the ice and taking it into the Nares.

Mercator salinity 0m and 34m, dec1-jan23, every 3days
added today's worldview image.  https://go.nasa.gov/2UbWItX

edit: except that everything about that image suggests current from the pacific side of Lomonosov.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 24, 2019, 09:29:55 PM
Introduction to Arctic Ocean circulation.

https://www.nature.com/scitable/knowledge/library/arctic-ocean-circulation-going-around-at-the-102811553
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 27, 2019, 09:54:04 PM
Off topic but testing ascat interferometry (A-team) here as it's 10MB. Showing december as well as it's more interesting pre SSW. Surprised that the line north of Greenland showed up (from quite early on) so it probably is low concentration ice that moves more than the ice surrounding it.
The old ice line is pretty clear too so may be useful for tracking over longer time frame.
3 days difference so the last 3 dates are invalid.
ascat interferometry(A-Team) 2018343-2019023
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 28, 2019, 06:00:03 PM
Mercator current 92m, jan2018-jan2019 for reference.
I didn't realise how strong the current from Kara to Laptev is.
ITP107 confirming turbulence north of utqiagvik (barrow)
whoi ITP103-110, jan28
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 29, 2019, 07:49:18 PM
Tracked the north Greenland dark line back to nov17 using worldview viirs brightness temperature (band15)night. Posting here as it's 6MB. There are many other parallel fractures heading towards the Fram Strait and some larger ones out of crop on the Beaufort side of the Lomonosov. Possible they are related to the ridge. I don't know why this one stands out so clearly.
With a clear line to focus on, it looks like a lot of ice melted and exported.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on January 29, 2019, 08:48:55 PM
Tracked the north Greenland dark line back to nov17 using worldview viirs brightness temperature (band15)night. Posting here as it's 6MB. There are many other parallel fractures heading towards the Fram Strait and some larger ones out of crop on the Beaufort side of the Lomonosov. Possible they are related to the ridge. I don't know why this one stands out so clearly.
With a clear line to focus on, it looks like a lot of ice melted and exported.

When you look at how much ice has moved towards the Barents, it is amazing how little ice is there.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on January 31, 2019, 12:40:43 PM
In previous years I've been intrigued by the persistent upwellings in the Beaufort say around 150/76 this year although there are signs of them on the salinity animation none on the lead opening (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortopening_nowcast_anim30d.gif) animation. though there are signs of persistent internal waves emanating from the Pacific[?].
So I took a look at the compressive strength (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength_nowcast_anim30d.gif) animation where they [IWs] are far more obvious, there's also an interesting sheer line caused by the rotating pack, springing from Prince Patrick island and close enough to suggest it's following the contours of the Canadian basin.
Finally looking at the Ice thickness (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortictn_nowcast_anim30d.gif) animation it seems the tides in Amundsen are forcing the ice to rotate much faster than in previous years, perhaps it's moving too fast for the upwellings to make an impact on the surface.
I've left the links to the animations because sometimes I 'get' more watching the animation develop.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 31, 2019, 08:32:22 PM
Thanks johnm33, some new things (for me) to look into.
A nice intro to internal waves from whoi here https://www.whoi.edu/oceanus/feature/the-waves-within-the-waves
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on January 31, 2019, 11:51:21 PM
Welcome, the 'Importance of Waves' thread has some good links too, which may be of interest, plus a variety of views.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 02, 2019, 03:53:20 PM
Nice thread. Any comments on this? ascat day28-32 (middle of the new dark ice)
It matches the compressive strength map pretty well, but what causes it?
edit: went back 50 days. Looks like it may be moon related.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 02, 2019, 10:35:44 PM
"Any comments" Still thinking, but the presistent high [slp] over the Arctic in january would cause some drop in overall sea level, then we have a significant low in Bering which would force tides a little higher. So maybe some Pacific water forced in pulses through the strait, that and some other factor, the thickest ice surged back rather than following it's usual [recent] trajectory towards Amundsen. It may be the other factor was a surge of Atlantic water falling out of St Anna trough creating a pressure wave against Greenland, accelerating the flows through Fram and Nares, once forced those currents would suck more water in their wake.
The ingress of Pacific water has caused some warming, if it was anywhere near as warm as the Atlantic we could see some serious evaporation. As it is we may see it break open some leads towards McKenzie once the new moon gets Amundsen pumping again in the next few days.
 The sheer line may be the result of a returning/reflected wave meeting the incoming but why would it be straight?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 03, 2019, 12:19:06 AM
Maybe it's related to the shear in the thicker ice on the edge of the Chukchi. Will try to tease out more detail tomorrow.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 03, 2019, 12:29:12 PM
If the waves are carried by the salinty layer that straddles 100m depth, then perhaps that layer is rotating faster than those below. Then the sheer  could be caused by a reaction between the incoming waves and any vortices induced on the northern 'front' of that rotating layer, in some sense the waves may be accelerated beyond coherence by there own accumulating torque as they approach the axis of rotation, and their energy added to that of the vortices present. ?
I'm gong to look back over the buoy data to see if anything shows there.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 03, 2019, 03:59:53 PM
Not sure that layer reaches so far but it's an idea. Did my best with an enlarged version.
ascat day15-33
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 04, 2019, 09:19:27 PM
Verifying with worldview viirsbt15n, jan21-feb3. Could be a combination of waves as there are parallel fractures both sides.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 04, 2019, 11:26:47 PM
Mercator does have a large salinity difference along that line at 0m, almost parallel with another further north. Similar at 34m. Could it be a thrust into the less dense water, sending a wave northwards, possibly reflecting back?
mercator 0m salinity, dec20-feb3

update on ITP103-110, feb4
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 05, 2019, 12:19:19 AM
That looks like Atlantification spreading from the CAA, surprising. A different salinity would affect the rate of propagation. I'm still not sure what caused the waves, too many over a short period to simply be tidal, the sheer line may be the northern front of the gyre. I'm not even certain what layer the waves are in.
 Take a look at this (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength/nowcast/strength2019012912_2019013000_930_beaufortstrength.001.gif), zoom in and decide if the twists in the waves are artifacts or real, then I have to wonder if the persistent grid perpendicular to the sheer could be real too, neither are common features.
I'd assumed the saline layer that straddles 100m reached to Lomonosov, it looks more likely that it's continuous over all the Arctics basins. 
Have to admit I'm baffled, as usual, about what goes on beneath the ice.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 05, 2019, 06:48:34 PM
Animated compressive strength charts to see how they match up (with post 144), jan27-feb4.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 05, 2019, 06:52:41 PM
Looking back through ascat to 2010 there are lots of surges but only one similar, less obvious, event in 2014, day 98-109. Anecdotally, the pack appears less mobile in previous years. Not sure how to quantify that.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: RoxTheGeologist on February 05, 2019, 07:06:25 PM

Is it possible to remote sense salinity with sea ice?

"Since no SMOS SSS can be derived over sea ice, only grid points with sea ice fraction lower than 30% have been used when comparing TOPAZ and SMOS SSS"

https://www.mdpi.com/2072-4292/10/11/1772/htm

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 06, 2019, 02:09:00 PM
Thanks for that RTG. Any examples from the 400MB data? I'm a bit tight on broadband volume and would need to budget for that.

Polarview image of the dark line north of Greenland in post 135. https://forum.arctic-sea-ice.net/index.php/topic,2417.msg187569.html#msg187569

Edit: While reading up on compressive strength I came across these crystal structure profiles in https://doi.org/10.1016/j.coldregions.2018.03.002 and wondered if they were perhaps relevant to this image. (scale on left is cm)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 07, 2019, 07:12:35 PM
Current surges at 34m into the Chukchi, mercator (model) jan1-feb6
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 10, 2019, 01:13:52 PM
Detailed view of part of the dark line north of Greenland in polarview before it hits the Fram Strait. Fairly sure now that it originated in the Laptev as shown.
ascat 2018074(mar15), 2018317(nov13) and 2019025(jan25)
polarview, feb5-7
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on February 10, 2019, 03:59:21 PM
That animation would sure seem to suggest that the transpolar drift is alive and well.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 10, 2019, 07:05:37 PM
That animation would sure seem to suggest that the transpolar drift is alive and well.
Or a huge broom sweeping the old ice out of the arctic ;)

All the whoi ITP buoys are heading north. 104 has gone off the map, 105 shortly to follow, hopefully not taking all the fresh water with them. Looks like 107 has some interesting data when it settles down. 109 and 110 sticking above the warm patch.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 12, 2019, 12:33:34 PM
update on mercator 0m salinity jul2017-feb2019.
Still wondering about the Lincoln Sea so here is CAA enlarged and speeded up to highlight long term movement.(same dates)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 12, 2019, 07:13:46 PM
update on mercator 34m salinity sep2017-feb2019. (scale same as previous post)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 14, 2019, 11:25:02 PM
update on ascat 2010-feb2019 for reference. (some gaps in data)
How to quantify mobility?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 17, 2019, 11:11:12 AM
An amateur attempt at visual identification of ice thickness using a comparison of ascat with an overlay of piomas thickness contours created using ImageJ edge detect for 2018.
Best efforts at scaling and alignment. Missing ascat days have been duplicated with nearest days. Poor data days remain for continuity. Off topic but posting here for reference.
thanks to wipneus, Zhang and Rothrock 2003 for piomas graphics and data
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 18, 2019, 12:42:02 AM
An even rougher attempt at visualising whoi ITP107 . The charts are made using octave and I think they are accurate, though they need some tweaking, but scaling and alignment with ascat are by eye for now. Other ideas are in the pipeline.
It looks like itp107 is struggling a bit at the moment. Turbulence or lost its tether?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sterks on February 18, 2019, 09:00:09 AM
That is a great presentation, Uniquorn.
The Gyre beneath is surely strengthening thanks to the strong drift in the right direction this winter.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on February 18, 2019, 10:35:49 AM
Yes the temp /salinity contours are not working right now on itp 107 but sometimes the profilers come back. The gyre is certainly cranking compared to last year however. Thanks for all the work uniquorn !
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 18, 2019, 11:19:01 PM
Thanks for the encouragement. My attention to detail is so poor that I didn't notice ITP109 was only reporting location till I ran the numbers, so here is ITP110. 103-105 data is different format so I may have a rethink about presentation before going further.
Any ideas how to accurately locate lat,long onto ascat?

Edit: Part of the motivation for putting these animations together was the large salinity drops in the profiles like those around day330 below. I had thought they were sensor problems but looking at the data like this I don't think so. Johnm33 suggested they were currents. That event does coincide with a rapid change in direction though.
Added the whoi locprof
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 19, 2019, 01:01:25 PM
Thanks for these animations of the bouys motions, tracking them and looking for some surface signs of the salinity changes is exactly what I've been thinking about.
 Fwiw I've persuaded myself that these changes are happening from below, a sign of accelerating Atlantification. Currents into Barents are increasing[?] forced by tides[?] and slp, when these waters fall into the deep they are generating waves in the deeper layers, so if they fall off the shelf the waves caused are more or less parallel to lomonosov and arrive to wash up the shelf on the Canadian/Alaskan side, mixing the layers and causing the +/- parallel waves that wash back in the surface layer. As these wash back they're heading straight back towards the rotational axis and gain rotational energy almost as fast as they dissipate it churning the ice. If the waters wash into the  StAnna trough they force their way into Laptev generating deep waves which can travel all the way to Banks/Amundsen, they generate some backwash from the shelves giving some interference patterns more or less at the 'focal' point of the curved shelf structure and are interfered with by the parallel waves coming from the shelf. It may be that the bouys are being damaged by deep waves travelling in different directions causing stress in the lines beyond their design limits.
It'd be interesting to find some evidence of unexpected tide heights/lows at Sachs Harbour
With the full moon and the present low slp in Barents we're probably going to see another series of unusual waves in Beaufort in a few days time.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 20, 2019, 11:53:36 PM
A couple of images which led me to believe the stirring of Beaufort is caused by deep disturbances, bouys 104 + 105, the pulses/waves[?] seem to occur about once every two days so some resonance other than tidal. These bouys are quite close, so the differences are as interesting as the similarities. Bouy data courtesy http://www.whoi.edu/page.do?pid=20781
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpuu.sh%2FCPgYg%2F56a1a41490.jpg&hash=5423b29cc78a40b8acf44bef0f01c006)


(https://puu.sh/CPgVb/01f63eb051.jpg)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 21, 2019, 12:16:15 AM
johnm33, agreed about the changes from below. The results of the last cool(ish), cloudy summer probably confirm that. At what speed do the waves in the deeper layers travel?
Yes, I noticed those bumps at the bottom, though quite often they are smoothed. I'll run the numbers on 104 and 105 and see if I can line them up meaningfully.

Posting the following mp4 to show how inaccurate the previous attempts at bouy locations may be. I took less care to line them up this time as the projection is clearly wrong. The background is quite good though. I think octave does plot polar stereographic projection, struggling to find out how.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 22, 2019, 12:25:51 AM
A couple of images which led me to believe the stirring of Beaufort is caused by deep disturbances, bouys 104 + 105, the pulses/waves[?] seem to occur about once every two days so some resonance other than tidal. These bouys are quite close, so the differences are as interesting as the similarities. Bouy data courtesy http://www.whoi.edu/page.do?pid=20781
Only showing salinity here from 250m (dbar) to 800m to show more detail at depth. The 2 day pulse may be related to up and down profiles. First animation shows all data, up and down are labelled.
Second animation shows only up data with the 2 profiles overlaid inset at bottom right. They appear to show a layer at 350m-450m pretty well.
Click on the images to run.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 23, 2019, 12:34:40 PM
Heat transport to the Arctic slideshow from National Oceanography Centre.
https://slideplayer.com/slide/12317656/
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 26, 2019, 09:27:38 PM
Mercator model doing quite a good job matching 34m temperature to Suomi npp/viirs on the atlantic side, feb26.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 26, 2019, 10:07:21 PM
A closer look at floes attempting to approach Svalbard, feb25-26 (some clouds)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 27, 2019, 12:14:02 PM
<>
 Take a look at this (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength/nowcast/strength2019012912_2019013000_930_beaufortstrength.001.gif), zoom in and decide if the twists in the waves are artifacts or real,<snippage>
johnm33, do you have a link for arctic wide hycom compressional strength? Beaufort only catches the edge of these...
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 27, 2019, 05:26:01 PM
No link, I guess the navy mainly operates in the Beaufort.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on February 27, 2019, 08:36:45 PM
I continue to be amazed by the depth of the Pacific Warm Water layer as evidenced by itp 110. If compared with two completed itp missions itp 78 or itp 85 we can clearly see the difference with current Beaufort conditions. Does anyone have any idea how this extra heat and volume will dissipate ? 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 27, 2019, 11:03:23 PM
thanks johnm33

<>Does anyone have any idea how this extra heat and volume will dissipate ?
Probably not but as we're on the cusp of the freezing/melting season here are some options....

1. It's a 'one off' that slowly fades away by mixing, adding to general AGW.
2. It's perennial and layer thickness and temperature increase yearly, eventually warming surface layer and reducing ASI.
3. Without the thick ice 'governor' the gyre spins up to unstable speed, the freshwater layer slips off into the CAB at the end of the melting season and freezes in place up to 20m thick. The warm layer radiates into space in clear skies and gives us another 10 years to save the planet. Marvel make a film about it. ;)
4.....your own wild guess
didn't mean to imply your ideas were wild Bruce Steele


edit: incoming from bering/chukchi or upwelling?
Worldview, terra modis, Beaufort feb27
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 28, 2019, 11:44:58 AM
'any idea'?
I'm reading the 'intrusions' in the temp./sal. contour plots (http://www.whoi.edu/page.do?pid=163197) as waves happening in the deeper layers. The lack of sea ice over Barents, which I suspect acted as a baffle, is allowing ever increasing volumes of Atlantic waters to fall into Santa Anna trough or down the face of the continental shelf, likely enhanced by tidal forces these waters arrive in pulses and are the cause of the deep waves.
Looking at 107 (http://www.whoi.edu/page.do?pid=163096)  I'm reading the white intrusions as off the scale, not faults, it's very difficult to guess the direction of the waves but if they originate from the Barents side they will wash up against the shelf somewhere on the US/Canadian side, and when they do some mixing must occur. 107 actually seems to show a vertical vortice penetrating well into the deep, a much more dynamic mixing than anything that can be seen at the surface.
If we have more Atlantic water penetrating into the Arctic then it will drive out the easiest fraction of the water there, the fresh surface layer.
edit: corrected link
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 28, 2019, 05:41:28 PM
<>I'm reading the white intrusions as off the scale, not faults,<snippage>
I don't think the white areas are off the scale. It looks like the profiler stops moving up and down the wire, possibly because the current is too strong. With its proximity to the Chukchi, isn't it more likely that the latest currents are related to the pulses from the Bering?

Some extracts from the whoi ITP technical description. http://www.whoi.edu/page.do?pid=20777

Quote
The profiling underwater unit is similar in shape and dimension to an
ARGO float except that the float’s variable-buoyancy system is replaced with a traction drive
unit.
Larger motor currents are observed at times of fast ice floe motion when larger
wire angles develop and drag forces on the profiler are increased.

A 250 lb ballast weight (made of 50 lb plates to facilitate transportation) is fixed to the
bottom wire termination to add tension to the wire and minimize its catenary. The WHOI
CABLE model (Gobat and Grosenbaugh, 2000) was used to determine the attitude of the ITP
mooring due to 25, 38, and 51 cm/s ice floe drift speeds using several different wire lengths. The
model predicts about 5 m of vertical uplift of the bottom termination at 25 cm/s, about 32 m at 38
cm/s and about 85 m at 51 cm/s. Horizontal displacement of the bottom termination is indicated
to be about 100 m, 220 m, and 350 m, respectively. To accommodate the catenary of the ITP
mooring at times of ice floe drift speeds up to 35 cm/s, 25 or 30 m of extra cable (beyond the
programmed maximum profiling depth) is needed. So mooring cables of about 790 m length
should allow for profiles as deep as 760 m in the vast majority of ice drift conditions. At the
extreme instances when drift rates approach 51 cm/s drift, it may be impossible for the profiler to
climb the wire against the current, making the maximum depth of the tether moot.

whoi itp107 location, temperature and salinity jan-feb  (click to run)
whoi itp location and profile contours feb28

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 28, 2019, 09:53:12 PM
Here looking at the path of whoi ITP107, data in previous post, overlaid onto Mercator 34m salinity. Still some inaccuracies in the scaling (shown in the final frame) as lat/long hasn't been converted to the correct projection yet.
Apparently not as close to the choppy Chukchi waters as I had thought, if Mercator model is correct. Good news if it goes round again (and the traction drive is ok).

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 02, 2019, 07:02:41 PM
On the pulses being from Bering, it's possible but the strait is shallow limiting the volume passing through, Pacific water is less saline so is less inclined to sink, then there's the complex bathymetry to dissipate any surge unless it breaks through north of Barrow.
   The periodicity of the waves bears no resemblence to the tidal surges and so must result from another dynamic I'm thinking of wave harmonics in the basin(s)  on the Barents side of Lomonosov causing surges breaking through either at Lincoln or Laptev and sometimes over the ridge directly, that's simply because it's hard to see where else the series of parallel[+/-] wave forms could evolve.
Looking at  hycom salinity (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif) the break-up of Pacific waters show, and if you zoom in there's some type of waves being generated breaking through the surface and radiating away from Laptev.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 03, 2019, 12:15:03 AM
Yes, thanks, the Bering Strait is too shallow. ITP110 shows the most regular disturbances at depth. 20-30 day intervals. That could also be due to circular drift over relatively stable currents though.


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 04, 2019, 10:52:22 PM
It occured to me later that the surges coming through from Bering might be responsible for the turbulence/vortice that [i think] happened to 107. Looking at the bathymetry there's a cut close to the coast which would channel the water. I suspect that when surges come through they behave a little like slime, hard to get them moving but once established the movement accelerates for a while then peters out. The "slime" body all has a similar energetic potential so when it meets the Beaufort gyre the two interact to create vortices. There's some evidence on amsr2 polarview of a streak more or less flowing out from where the channel is around 08:02 and again now so should be a good test of the idea.
(https://puu.sh/CTeEq/231b03dc79.jpg)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 05, 2019, 12:10:10 AM
Thanks johnm33. A suggestion to look at density led me to the ocean water density calculator.
Density in kg/m3 (cubed) for ITP110


http://www.csgnetwork.com/water_density_calculator.html
Quote
The equation used in this calculator can be found in:
Millero, F, C. Chen, A Bradshaw, and K. Schleicher, 1980: A new high pressure equation of state for seawater, Deep Sea Research, Part A, 27, 255-264.
doi:10.1080/15210608209379435

I may have time to look at 107 again tomorrow
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 05, 2019, 01:42:46 PM
Stayed with ITP110 to look at density compared with temperature from 0-150m (to keep Bruce Steele interested ;) )
The build up in temperature from 40-100m in some areas speaks for itself. It's above my pay grade to comment further.
Up and down profiles shown
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 05, 2019, 03:56:26 PM
'above my pay grade' mine too, just thinking out loud
So I've still been looking at hycom salinity gif (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif) at 300% areas of interest to me are 120-30E/80N 145E/85N 0/86N and the pole through the 30E/150W meridian
No idea if i've just missed this before but definite signs of harmonic waves and breakthroughs in more or less the places the bathymetry would indicate.
(https://puu.sh/CVpvE/bab273b98c.jpg)
Given it's gyrations no reason not to think some/all of the intrusions 110 shows are vortices too.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sterks on March 05, 2019, 04:21:10 PM
Above my pay grade too, I am not as fascinated by the heat pulses (all kinds of dragons down there it seems, jets, vortices and whatnot storing heat excess) but how nice and stable the lens of fresher cooler water seems over all that time and locations. I wish these data had been captured in part under the 2012 or 2016 GACs, only thing with strength to disrupt that layer with thin or scattered ice.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 05, 2019, 09:16:06 PM
ok, no paygrade excuses then  ;) or we all get a rise  :) . I looked at itp53 http://www.whoi.edu/page.do?pid=157836 which is a prime candidate for 2012, but it requires a bit of recoding as the file format has changed. It would be interesting to compare though.

Regarding the lomonosov ridge there have been many parallel fractures this freezing season. I didn't notice them so much last year and viirs brightness temps aren't available before then. They would have to be pretty big to show up on ascat.

I guess that mixing is more likely to occur with shallow density gradient.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 10, 2019, 01:06:06 PM
I've been looking at 105 (http://www.whoi.edu/page.do?pid=163456) again.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpuu.sh%2FCXRYR%2F2757a79557.jpg&hash=f708f091aabdfc4d20546147b30cd9cf)
 It's situated in water about 3650m deep if the white intrusions are off the scale vortices how likely is it that they'?' reach almost another 3km deep? Perhaps they are large bodies of 'native' deep Fram (https://geology.com/articles/arctic-ocean-features/) basin waters forced over Lomonosov by either wave action or surges from Santa Anna trough.
 The separation of the various fractions of density/salinity around the cores is exactly what one would expect from vortices. Is it one vortice that the bouy makes repeated passes through though? Whatever thats a huge amount of water to be moving coherently away from the axis of rotation.
added, 104 seems to be encountering something similar http://www.whoi.edu/itp/images/itp104dat3.jpg
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 13, 2019, 09:42:03 PM
I've been looking at 105 (http://www.whoi.edu/page.do?pid=163456) again.
Some data for whoi itp105. It appears to be programmed to collect 3 profiles down to 250m then 1 down to 800m if it has time or doesn't have a problem. That makes it tricky to match up dates with my simple coding skills so I haven't attempted to combine much.
Firstly, the location data. For the timeline in the image you posted it doesn't look like it makes repeated passes. (or maybe it does, please check)
2. Temperature and salinity from 300-800m (some days have no data) click on the image to run
3. Temperature and salinity from 0-250m. Had to go to mp4 to keep the size down.

edit: last profile was mar9. Hope it comes back.. Forgot whoi itp105 location and profile.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 14, 2019, 12:36:08 AM
update on mercator 34m salinity, jan1-mar12
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 14, 2019, 06:16:38 PM
The salinity depths at mercator suggest it's more likely that the vortice water 'bodies' are coming in from the direction of Lincoln sea, along the shelf, then, given the density of the water, sliding down to follow contours into the deep. Perhaps as they evolve they become first more bell shaped and then ovoid discs as they lose spin thus sucking down water even as they move south into Beaufort, at least that's the best guess I have for the down-draughts on 109-110.
I was checking out Copernicus (http://marine.copernicus.eu/services-portfolio/access-to-products/) too, 001 024 amongst others, they suggest that CAA has been 'colonised' by Atlantic water at depth, part of the same inflow leading to the vortices, I wonder if that has led to the build up of the Beaufort 50-100m warm layer, only the top freshest layer escaping above it? and yet Baffin so far shows little sign of warming.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 15, 2019, 10:30:04 PM
I had hoped that showing the data in a different format would clarify what is happening between 300-800m but I can only see that some event occurs and the sensors get stuck on the line. Possibly turbulence but no measurements.

This looks interesting though data is only up to 2015 and it concentrates on 0-150m.
Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean.
http://science.sciencemag.org/content/356/6335/285.full
DOI: 10.1126/science.aai8204
Quote
The deep winter ventilation and the disappearance of the CHL in the eastern EB (eastward from Severnaya Zemlya, >90°E) at several mooring sites in 2013 to 2015, however, are unprecedented (Figs. 3A and 4). Substantial changes in seasonal heat content Q (see definition in the supplementary materials), driven by surface cooling and salinification during winter sea-ice formation, occurred in the upper 130-m layer at M3e, M13, M16, and M6b mooring sites. If this trend persists, convectively driven winter development of the deep (>80 m) SML, combined with ventilation of the upper 130-m ocean and associated disappearance of the CHL would represent a fundamental change, with the eastern EB water-column structure becoming less stratified and susceptible to further mixing.

I'll find out what a wavelet transform is and see if that helps....
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 15, 2019, 11:20:40 PM
A plug for https://cryospherecomputing.tk

Regional cumulative albedo-warming values (anomaly) 1979-2018

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 16, 2019, 03:41:08 PM
^click to animate^
I suspect there's counter rotation between the top and bottom of the vortices, so the forces at the 'pinch' would be very destructive, if 105 passed through the center _ _ _
This compares the last 4 years of the apparent waves/pulses showing in the salinity from hycom, which incidentally also show at depth in mercator. [19-18-17-16]
(https://puu.sh/D0Z7A/d32cc1e2af.jpg)
   Whilst there's some signs of pulses in other years they aren't persistently delivering turbulence along Lomonosov towards the pole. Mercato (http://bulletin.mercator-ocean.fr/en/PSY4/animation)r 30m salinity, difficult to pick out but the same pattern is showing just east of 120E, again delivering pulses towards the pole, and spilling Atlantic water over the ridge.I think.
added last para.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 21, 2019, 12:39:20 PM
Is there a 3d representation of arctic ocean topography/bathymetry anywhere?

Update on the whoi itp buoys. Some caution is needed with the animation as some of the profiles stopped being received some time ago, particularly itp89, included for the drift path, itp103, 107, which has been stuck for a while, and itp109.
The 3 northernmost buoys still drifting steadily northwards against the annual drift.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Tor Bejnar on March 21, 2019, 02:46:54 PM
Quote
Is there a 3d representation of arctic ocean topography/bathymetry anywhere?
Try the Arctic Maps (https://forum.arctic-sea-ice.net/index.php/topic,417.msg29713.html#msg29713) thread [another here (https://forum.arctic-sea-ice.net/index.php/topic,417.msg153122.html#msg153122) and down-thread, including the most recent post].  Of course, an internet search for "Arctic Ocean Bathymetric Map" will come up with more.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 21, 2019, 07:37:13 PM
Thanks Tor. I found this one that helps (me) visualise the scale of the depth of the basins and where deep waves are most likely to cross the Lomonosov Ridge. It's quite good for the Fram Strait too.
No scale but I can find depths elsewhere.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 23, 2019, 12:41:12 AM
Looking at 107 (http://www.whoi.edu/itp/images/itp107dat3.jpg) there seems to have been a large scale 'sea change'. After the idea that the Atl. waters coming through Fram may be responsible for the vortices passing 104/5 and that with 105 there was a distinct possibility that this Atl. water was reaching into the deep to follow the contours I followed the 'deep' and found it ran very close to the western side of the Canada basin approaching the continental shelf close to 155w. That makes some sense given the surface waves propagating more or less parallel to the shelf thereabouts recently but it also indicates the [possible] arrival of Atl. waters beneath 107 . The 'off the scale' white at depth may indicate the arrival of large amounts of Atl. waters for a much longer period, given the persistence of the change I'm guessing that the energetic potential of the Atl. water is keeping it tight to the western edge of the basin, even so this seems to be quite a significant change.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 23, 2019, 01:04:54 AM
itp107 has only been able to move short depth changes between 200m-350m since day58 (423 on the chart I think) and sporadic for a some days before. The chart doesn't represent that very well.
ftp://ftp.whoi.edu/whoinet/itpdata/itp107grddata.zip
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 23, 2019, 01:51:09 PM
Thanks johnm33 for making me run the numbers again on itp107. Apologies for bad scaling on salinity for days 45-46.
whoi itp107 location, temp and salinity 2019 day21-81 click on image to run
Screenshot of data for day45.
There is a lot going on down there. It's a shame the sensors can't move enough to show it.

 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 23, 2019, 02:07:33 PM
whoi-itp107 salinity 2019 day21-81 speeded up to show the anomalies.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 24, 2019, 01:17:57 PM
Looking at 156 (https://forum.arctic-sea-ice.net/index.php/topic,2417.msg188793.html#msg188793)/7/8 animations some of the things I'm suggesting already seem to be there, just couldn't see them til' I looked for them. What I was particularly interested in was the increasing Atlantification of the shelf waters in Laptev through ESS, it appears the saline Atlantic waters are stopping the Siberian freshwater from entering the Arctic in it's accustomed way and that it is only entering much further east, where the inflow from Bering is being forced west and mixes with it. Thus the 'ridge' of thick ice being formed further east one could say at the confluence of the gyre and the incoming Atlantic stream. That may be responsible for the increasing depth of the 'Pacific' layer.
 The more or less random pulses of Atlantic waters coming through Fram on their way to Nares is there to be seen too, as is the flow which is likely generating the gyres which are dropping into Beaufort and Atlantifying it's basal waters.
I don't know if the Davis Strait array is functioning or if/when the data is accessible, I guess an alternative would be a record of expected and actual tides from somewhere on Baffin Island to give some clue about how much fresh-water is escaping. Higher low tides = more imho.
I'm beginning to think I must have upset a Chinaman, interesting times.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 24, 2019, 06:49:06 PM
posting here for smaller readership as it may be rubbish. Worldview, terra/modis nares, mar23-24.
Can I see waves? click on image to run.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 24, 2019, 10:48:14 PM
What I was particularly interested in was the increasing Atlantification of the shelf waters in Laptev through ESS<snippage>
I think I see evidence of the Atlantic in the Laptev and maybe that is not helping the thin wind driven ice north of the Anzhu islands. All should become clearer over the next few weeks.
Worldview terra/modis ess/laptev mar16-24
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 26, 2019, 02:26:04 PM
I couldn't find any recent data for the Davis Strait array. Does anyone reading have access?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 27, 2019, 12:56:07 PM
Comparison of whoi itp89 and 110 with drift speed and buoy temperature. Their drifts cover a similar path east of the Mclure Strait and the profiles show the tenperature difference at 50-100m between 2016 and 2019 (different months though, I think). edit: note salinity below 400m
itp89 is still stalwartly reporting buoy temperature despite spending 2 winters iced up in the Mclure strait then Viscount Melville Sound. The profiler is was only changing depth a few metres per day when it stopped profiling in 2016, similar to itp107 but perhaps it will drift back into the main channel when melt starts. Buoy temperature is a handy 'on the ground' reference. http://www.whoi.edu/page.do?pid=148096

worldview terra modis mar26. x marks the spot, rough location of itp89

edit: On another note itp103,4 and 5 all still heading north east against the annual ice drift
edit2: all profiling from itp89 stopped day250 2016
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on March 28, 2019, 10:54:15 AM
Had to check the depth in McLure it barely goes deeper than 400m, it's interesting that the outflow seems to be from the upper layers. http://elevation.maplogs.com/poi/sachs_harbour_nt_canada.437131.html best full screen and zoom out a little.
OT but I'd never really noticed how smooth some of the otherwise rugged looking coasts were in the CAA, makes me think very soft rocks or more likely yedoma. The steepness of the drops offshore are remarkable too.
added, for elevation click on the point of interest, +doesn't work for me now either.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 02, 2019, 03:14:37 PM
Elevations didn't work for me from maplogs.com but it was interesting to see the coastline without the ice.
Decided that I'd ignored sea surface height for long enough. Here is mercator's model from jan2018-mar2019.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 04, 2019, 10:37:16 PM
mercator 34m salinity overlaid onto ascat, jan2018-apr3(2019) as a rough guide to arctic atlantipacification.
The stutters are due to missing ascat data, nearest days have been duplicated. The mercator scale is not really relevant as the overlay changes the hues but red is saltier than blue. Using 34m salinity here as 0m tends to change rapidly with ice melt and hides the underlying currents.
Ascat swaths leave rotating data gaps at the periphery, summer and seas are a swirl of 'weather' so once again, hazard warning.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 06, 2019, 01:48:18 PM
It seems that Pacification is really happening right now, in front of our eyes.


I think we know that Nino events can , via Kelvin waves, push warm surface waters up the U.S. coast and into the basin via Bering?

Now we are in a low grade nino event but no big Kelvin waves have really had impact but we should remember the state of the Interdecadal Pacific oscillation since 2014?

Since 2014 this natural forcing has been in its positive state. This means that, over its area of influence , warmed surface waters are present ( instead of being buried in the upper ocean?) .Will this mean twenty odd years of ever warmer surface waters pushing in from the Pacific side of the basin?

It's early days but maybe we have left it long enough to expect more melt over the Pacific side as Pacific ocean currents begin to deliver these warmed surface waters ?
Not familiar with PDO. I hope Gray-Wolf doesn't mind the repost here for reference.
From NOAA https://www.ncdc.noaa.gov/teleconnections/pdo/
Quote
The Pacific Decadal Oscillation (PDO) is often described as a long-lived El Niño-like pattern of Pacific climate variability (Zhang et al. 1997). As seen with the better-known El Niño/Southern Oscillation (ENSO), extremes in the PDO pattern are marked by widespread variations in the Pacific Basin and the North American climate. In parallel with the ENSO phenomenon, the extreme phases of the PDO have been classified as being either warm or cool, as defined by ocean temperature anomalies in the northeast and tropical Pacific Ocean. When SSTs are anomalously cool in the interior North Pacific and warm along the Pacific Coast, and when sea level pressures are below average over the North Pacific, the PDO has a positive value. When the climate anomaly patterns are reversed, with warm SST anomalies in the interior and cool SST anomalies along the North American coast, or above average sea level pressures over the North Pacific, the PDO has a negative value (Courtesy of Mantua, 1999
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 08, 2019, 12:39:23 AM
melt pond testing. Clouds are there...
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 09, 2019, 07:11:05 PM
Following up on this post:
Crackification on the Atlantic side continues.
ascat resolution doesn't really pick up the fracture in the thicker ice but it shows clearly in the darker area north of laptev on day91 with more fractures further south in the following days. The wind across the laptev changed 3 days ago so probably not related. The southerly fractures fit well with the bathymetry though.
ascat day85-98 forward and back.
ascat day98 with NOAA bathymetry map overlaid.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 10, 2019, 12:01:23 AM
update on polarportal.dk ice surface temperature, feb1-apr8
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 10, 2019, 01:16:59 AM
cs2smos merged sit, mar-apr7 for reference (not fixed scale, will look at that. Limited panoply skills)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 11, 2019, 11:56:58 AM
update on the laptev lomonosov fractures
ascat day89-100, forward and back.
worldview terra modis, high contrast, apr7-11, ascat apr7-10 inset.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: be cause on April 11, 2019, 12:50:06 PM
we could do with a plug for the .. but Ill not go there .. :) .. b.c.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 14, 2019, 11:18:18 PM
A comparison of mercator(model) 318m salinity, feb1-apr13, 2018 and 2019. The reason this thread was started.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 15, 2019, 09:43:24 PM
reposting comparison of bering to laptev mercator(model) 0m salinity, feb1-apr13, 2018 and 2019 for reference. Note high salinity in southern laptev.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 16, 2019, 11:37:37 PM
The good people at the woods hole oceanographic institution are once again posting active itp buoy data. This animation only showing those with full depth profiles.
https://www.whoi.edu/page.do?pid=163196
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 19, 2019, 07:56:59 PM
Following up on the laptev lomonosov fractures here is ascat and piomas apr1-15(ish)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 22, 2019, 03:25:41 PM
50 days of ascat (to apr20) with NOAA bathymetry overlaid at 22% transparency.
Looking mostly to see how the laptev fractures fit in to the bigger picture. Also interesting is nares/lincoln,  chukchi plateau and east greenland albeit at low resolution.
Never noticed before that it's shallower where the Oddenham ridge once formed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 22, 2019, 09:47:54 PM
mercator-salinity-0m-34m-92m-318m--arctic-jan1-apr21.
Had this set up for nares, posting full arctic for ref..
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on April 30, 2019, 11:00:51 AM
Looking at the above animation and, https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif zoomed fully in on the CAA. It seems that Pac. waters are penetrating along the coast even into Amundsen, and beyond where they are stirring up the fresher deep water, and I assume slowly replacing it. The current flowing through to Lancaster sound via Franklin strait suggests it still has the signature of Pac. energy and has been remarkably persistent, coincident with the Beaufort high. From the north it appears Atl. waters have penetrated the garlic press and are 'colonising' Mclure-Lancaster NWP and mixing there with the Pac. waters.
 If this persists the CAA will melt out and there's going to be nothing to inhibit the freshwater lens of Beaufort passing through to Baffin/Labrador, which in turn suggests much greater penetration of Atl.+Pac. waters into the Arctic.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 30, 2019, 11:02:52 PM
It's a shame hycom don't have a 34m model to compare. Agree with the interpretation but where to look for verification? I suppose Nares opening early is one. Amundsen has melted much further east this year....
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 03, 2019, 10:06:07 PM
Worldview terra modis amundsen apr1-may2
uni-hamburg amsr2-uhh mar19-may2 2016 overlay
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 04, 2019, 09:32:37 PM
nasa nsidc daac ease-grid sea ice age v4.1 for 2018 (cropped to >1yr ice to reduce file size)
OT but here for ref
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 07, 2019, 01:45:30 PM
update on amundsen gulf, worldview aqua modis (clearer) may7, heavy contrast. This area only frozen fast since apr1.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 08, 2019, 10:08:52 PM
whoi itp110 for Bruce Steele. The warm layer getting thicker again as 110 drifts south west.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 11, 2019, 10:33:13 PM
Possibly a similar surge last year. Looks different though.
Worldview aqua modis, north greenland may11, 2018 and 2019. This year coincides with an event along the CAA coast and, of course, the Nares is open. Less resistance. Might even be sucked. Sure there's a better term than that.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on May 12, 2019, 12:00:21 AM
Wondering if the more powerful flow through Nares leads to a more powerful backwash as it temporarily stalls/reverses? again and again?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 12, 2019, 08:00:39 PM
Could be. Maybe b_l will take a look at the Nares entrance and see what comes up.

Reflection of weather event entering chukchi on day119 causes CAA lift off?
ascat day114-131 5days/sec
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on May 12, 2019, 08:16:34 PM
Wondering if the more powerful flow through Nares leads to a more powerful backwash as it temporarily stalls/reverses? again and again?

John, how do you mean backwash? What would i have to look for exactly? The amplitude of tides in the horizontal direction?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on May 13, 2019, 11:51:59 AM
backwash If a powerful current is flowing and it gets stalled by a tidal surge, for instance rushing up from Kane then I suspect the flow of the current stalls and pressure waves build up and are expressed by upward and sideways movement from the current generating various eddies in the process, then the current resumes, rinse repeat, - - I think?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 13, 2019, 10:23:26 PM
Cross posting mercator salinity 0m and 34m, apr4-may10 for ref.
Worldview aqua modis apr6-may13. Lincoln sea events well documented on the Nares thread.
uni-hamburg amsr2-uhh shows the CAA lift off more clearly than ascat above. (click to run)
Widening gyre driven fractures till apr29. Wind changes to southerly on may1 causing small lift off.. Anticyclone with northerlies over central CAA till may5 closing it. By may7 southerlies across central CAA cause larger lift off and by may10 easterlies from Fram strait meet with the southerlies to cause the humped fractures over north of ellesmere. nth greenland fractures not helped by the incoming atlantic current.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Stephan on May 13, 2019, 10:47:58 PM
Thanks a lot for these animations.
Doesn't look too good for the ice in the whole region from SE Beaufort up to the Fram Strait entry...
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 14, 2019, 10:36:05 AM
Despite the wind based description above, this still looks more like an ocean driven event to me.
noaa bathymetry overlaid onto heavily contrasted uni-hamburg amsr2-uhh may6-13 foward and back (hasty attempt-gotta go gardening ;) )
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on May 15, 2019, 10:44:25 PM
Looking again at the break-up north of Greenland, I noticed on hycom th (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticictn_nowcast_anim30d.gif). an almost simultaneous series of internal waves[?] breaking though in Beaufort near Amundsen, then looked at nullschool (https://earth.nullschool.net/#2019/05/10/1800Z/wind/surface/level/overlay=mean_sea_level_pressure/orthographic=-42.86,82.60,512/loc=-140.921,70.407)   and as well as the low in the north Atlantic helping water pass north of Iceland-Faroes there was a distinct drop in pressure just off the coast in Beaufort [10-11]which probably assisted the Atlantic waters inflow and led to the breakaway of the thick ice along the CAA coastline. I can't think of any occasion short of the last few days of the melt-season when that area has looked so vulnerable.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 15, 2019, 11:01:57 PM
Yes. Still looking at it. Here's ascat overlaid onto unihamburg amsr2uhh(heavy contrast), apr24-may14. I still think it's the push from the pacific into the chukchi that causes it. There's a compression from the atmospheric weather into the caa then upwelling or disturbance when the waves hit along the coast. Then reflection out into beaufort.
Will try to look more at the hycom ani tomorrow. It's a better illustration of the movement.
edit:not related, but interesting how the fractures north of ellef ringnes match up with the scatter difference.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 16, 2019, 12:25:16 AM
High pressure and clockwise rotation of the ice pack induce Eckman upwelling in the near shore waters of Alaska and Canada. The Coriolis effect deflects the ice towards the center of the high and it is replaced by water from below. If high pressure persists it slowly pumps up warm water from the Atlantic layer along the continental shelf.

At the moment little reason to suppose sea ice loss will accelerate, which makes the general disintegration of the sea ice all along the Arctic ocean edge from the Beaufort to the Greenland Sea all a bit of a mystery to me.

Persistent high pressure in May June and July is not good for Arctic sea ice, especially in the Beaufort sea.
perhaps because the caa coast is the one place where the ice isn't really rotating
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on May 16, 2019, 06:34:52 AM
The eastern CAA has just barely started moving. I was thinking about the Mackenzie river delta region when I wrote that. It has both upwelling and river water.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 16, 2019, 10:07:16 AM
Thanks for the clarification FOoW. I didn't notice the green text was a quote.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on May 16, 2019, 10:37:51 AM
Someone's not reading Gerontocrats reports carefully!  ::)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 16, 2019, 11:59:50 AM
True, I mostly look at the numbers but there was also this... https://forum.arctic-sea-ice.net/index.php/topic,2649.msg199429.html#msg199429

It would be easier to understand if the caa coastal ice was rotating but in the last 9 days it has hardly moved westward. Just north and south. The gyre driven ice slipping by the 'thick ice' north of caa.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 20, 2019, 10:39:06 PM
whoi itp110 salinity looks unusual from day105-120, (apr14-19, profile 413-443) https://www.whoi.edu/page.do?pid=163197
day109 data 12m-90m below

%ITP 110, profile 422: year day longitude(E+) latitude(N+) ndepths
2019  109.25141  -134.3791  74.1888  375 0
%year day pressure(dbar) temperature(C) salinity oxygen(umol/kg)
2019  109.25177   12   -1.5098   28.5838  184.7593
2019  109.25183   14   -1.5091   28.4931  195.4595
2019  109.25191   16   -1.5086   28.4130  205.3583
2019  109.25201   18   -1.5081   28.3412  212.2450
2019  109.25210   20   -1.5078   28.2903  216.1363
2019  109.25219   22   -1.5075   28.2615  217.7087
2019  109.25227   24   -1.5072   28.2385  217.6469
2019  109.25235   26   -1.5069   28.2252  216.4158
2019  109.25244   28   -1.5063   28.2195  214.5133
2019  109.25252   30   -1.5056   28.2078  211.7976
2019  109.25260   32   -1.5052   28.2038  209.3528
2019  109.25269   34   -1.5047   28.1997  206.8115
2019  109.25277   36   -1.5043   28.1916  204.1676
2019  109.25285   38   -1.5041   28.1701  202.3795
2019  109.25294   40   -1.5053   28.1295  202.2120
2019  109.25302   42   -1.5074   28.1066  203.7017
2019  109.25311   44   -1.5056   28.0840  205.3730
2019  109.25319   46   -1.5011   28.0746  207.2045
2019  109.25328   48   -1.4626   28.0411  207.3436
2019  109.25338   50   -1.1448   27.7462  203.9530
2019  109.25346   52   -0.8278   27.4566  200.9226
2019  109.25355   54   -0.6948   27.3505  199.7994
2019  109.25363   56   -0.6210   27.3089  198.5083
2019  109.25372   58   -0.4989   27.2259  195.8627
2019  109.25380   60   -0.4030   27.1750  194.4695
2019  109.25388   62   -0.3251   27.1523  195.4071
2019  109.25397   64   -0.2430   27.1630  198.0447
2019  109.25405   66   -0.1234   27.2234  204.6875
2019  109.25413   68   -0.0664   27.3863  216.4030
2019  109.25423   70   -0.0609   27.5189  229.5733
2019  109.25432   72   -0.0484   27.6743  238.4603
2019  109.25441   74   -0.0097   27.8478  242.8352
2019  109.25449   76    0.0471   27.9405  248.0106
2019  109.25458   78    0.0681   28.1058  255.3205
2019  109.25466   80    0.0575   28.4758  265.1770
2019  109.25474   82    0.1238   28.8198  275.2943
2019  109.25483   84    0.1752   29.0430  282.4478
2019  109.25491   86    0.1714   29.2519  286.3756
2019  109.25499   88    0.1259   29.4694  287.2250
2019  109.25509   90    0.0811   29.6863  285.4066
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on May 23, 2019, 11:17:37 AM
"I still think it's the push from the pacific into the chukchi that causes it"
Yes it looks like the Pacific water pushed in to the Arctic both sides of Chukchi plateau and it's energy transited across, probably also causing both the recent bottom melt that passed across the ice like a shadow[turbulence?] and forcing the thicker ice west as a consequence.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 23, 2019, 10:10:37 PM
<snippage(large)> If there is an operative Alaskan coastal current, it cannot be on the surface as countercurrent surface ice eddies are not seen (unlike in East Greenland).<snippage(large)>
Net annual export is roughly 44,000 cubic km per year from the Arctic to Baffin Bay, a small portion of sverdrups coming in with the West Spitsbergen Current or leaving via the East Greenland Current.<snippage(large)>
Agreed. Even the rammb sliders I've looked at don't show any ice eddies(so far). Obviously they are present at the chukchi/beaufort boundary and mercator model would appear to show an occasional current sinking to 34m or lower. Depending on interpretation that could be seen as upwelling though.
There is this from https://link.springer.com/article/10.1007/s10584-012-0576-4
Quote
Fresh waters originating in the Pacific, in the Atlantic and in Arctic rivers can be distinguished via chemical signatures. For example, Pacific water has a distinctive neodymium signature imparted by the weathering of volcanic rocks that comprise the Pacific Rim (Goldstein and Hemming 2004); such rock is enriched in 143Nd via the radioactive decay of 147Sm, which is itself enriched in the mantle where the magma originates. The high 143Nd/144Nd ratio in Pacific water differs from those of Atlantic and river waters, which contact old continental crust.

Samples for analysis were collected during the IPY-GEOTRACES program in the southern Beaufort Sea. The high measured ratio of neodymium isotopes reveals a presence of Pacific freshwater even at great depth in the Canada Basin (Porcelli et al. 2009). Low salinity water from the Pacific can only reach such depth if its salinity is greatly enhanced via extreme ice growth, likely in flaw leads near the coast. The IPY study of neodymium therefore provides a new means to trace rare ventilation of the Arctic basins by Pacific water.
with an interesting take on temp/salinity I hadn't seen before shown below.
Limited readership here unless you post long animations ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 23, 2019, 11:47:58 PM
whoi itp103 internal buoy temperature reached 10C today, which probably says more about sunshine than air temperature. I won't post these temps on the melting thread again as they could be misleading. Thanks Bruce.
https://www.whoi.edu/page.do?pid=163356
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 26, 2019, 12:26:28 AM
for reference, a rough overlay of global hycom cice ice thickness (GLBb 0.08-93.0) over ascat at 42% transparency.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on May 28, 2019, 03:03:07 PM
This is a GIF showing salinity at 30m 01.01. to today.

Are Atlantic waters soon mixing with Pacific waters? And could that have effects on the Beaufort Gyre?

Very big file due to a lot of days stitched together, sorry.

(i feel you petm  ;) )
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: kassy on May 28, 2019, 03:49:41 PM
It would be cool to have some bathymetric overlay for that type of map.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on May 29, 2019, 09:55:33 AM
Sorry Kassy, i'm afraid this is beyond my abilities. :(
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on May 29, 2019, 09:57:50 AM
Mercator model, salinity 0m vs. 30m for the month of May.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on May 29, 2019, 04:32:52 PM
I looked a little deeper, I ctrl+ this to 170% and play at 200
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20190401/20190527/2/4
it seems Atlantic water has circumnavigated the Arctic at depth.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on May 31, 2019, 10:35:53 PM
New development in Beaufort? https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength_nowcast_anim30d.gif
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 02, 2019, 10:03:31 PM
^ Error I meant to post this which if I'm not mistaken is showing the melt taking place as deep Atlantic water is sucked into and washed out of Amundsen and Mclure. This could be good or bad since it seems the surface will be fresher for the whole gyration, but unless the outflow of Fram/Nares slow it won't matter[help].
(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortsss_nowcast_anim30d.gif)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 03, 2019, 10:43:51 AM
I'm reading these three images as indicating the increasing penetration of Atlantic water, it has now, at depth, surrounded Greenland and most of Ellesmere. The third one shows how much it has penetrated along the CAA continental shelf. Whenever there's a tidal forcing or a low/high moves into/over the basin the deep water will wash up onto the shelf increasing bottom melt.
This will help in the opening up of the CAA to increasing ice export.
Then we have the increasing temp and melt spreading down Greenlands west coast from Nares all the way to Disko where the Irminger current brings it's own warming waters to.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic-bulletin.mercator-ocean.fr%2Fimg%2F-1%2Fpsy4qv3r1%2F20190601%2Farc%2FA%2Fpsy4qv3r1_20190601_arc_salinity_34m.png&hash=e326fab3fbf882874a8d462594da682f)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic-bulletin.mercator-ocean.fr%2Fimg%2F-1%2Fpsy4qv3r1%2F20190601%2Farc%2FA%2Fpsy4qv3r1_20190601_arc_salinity_92m.png&hash=e5b93921314557a9198768181bd50d32)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fstatic-bulletin.mercator-ocean.fr%2Fimg%2F-1%2Fpsy4qv3r1%2F20190526%2Farc%2FA%2Fpsy4qv3r1_20190526_arc_salinity_318m.png&hash=e86932366e1e8ccbd0641c0643a4f7d7)
https://earth.nullschool.net/#current/ocean/primary/waves/overlay=sea_surface_temp_anomaly/orthographic=-53.36,71.85,1389/loc=-61.503,75.588
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 03, 2019, 11:51:06 AM
This might be better placed in the stupid question thread, but why isn't the west coast of Greenland so salty at 0m? Shouldn't we see some freshening (i.e. blue tones) due to melting here too at least somewhere along the coastline?

Oh wait, it is actually doing that. Sorry, never mind.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 03, 2019, 12:46:03 PM
The glbhycom (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif) shows it up better, the denser Atlantic water is energetically driven against the coast forcing the fresh water into central Baffin, where it joins the Arctic waters who's relative inertia keeps them to the Canadian side. The difference in density means the Atlantic waters can constantly stream into the fjords whilst the fresh-er water exits on the surface. This can only get worse through to sept.
Ignore the warning to the link, it's a US navy website best zoomed in on rather than displayed 'forum' sized
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 03, 2019, 01:05:41 PM
That's very interesting! Thanks a lot, John.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Stephan on June 03, 2019, 07:49:39 PM
The glbhycom (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif) shows it up better, the denser Atlantic water is energetically driven against the coast forcing the fresh water into central Baffin, where it joins the Arctic waters who's relative inertia keeps them to the Canadian side. The difference in density means the Atlantic waters can constantly stream into the fjords whilst the fresh-er water exits on the surface. This can only get worse through to sept.
Ignore the warning to the link, it's a US navy website best zoomed in on rather than displayed 'forum' sized
I have no access to this website for weeks now (using Chrome as web browser). Is there any other chance to access this valuable information?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 03, 2019, 08:01:02 PM
Stephan, are you using http instead of https in the URL by chance?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 03, 2019, 08:46:41 PM
This animation (http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20190501/20190601/11/1) shows the temp. anomaly growing and moving south from Nares
Not as good as an animation, the sss from hycom
(https://puu.sh/DB93E/6482d79ad5.jpg)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 04, 2019, 12:32:44 AM
worldview aqua modis overlaid onto mercator 34m salinity at 50%, jun1-3
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 04, 2019, 07:46:40 AM
Hey Uniquorn, glad to see you posting again. :)

Would it be possible to have this for the 0m salinity too?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 04, 2019, 10:28:09 AM
Very busy here at the moment.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 04, 2019, 10:35:18 AM
No hurry. :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Stephan on June 04, 2019, 07:02:03 PM
Stephan, are you using http instead of https in the URL by chance?
If I write https in the URL it is marked in red and striked through. This is the message that follows:
"Dies ist keine sichere Verbindung
Hacker könnten versuchen, Ihre Daten von www7320.nrlssc.navy.mil zu stehlen, zum Beispiel Passwörter, Nachrichten oder Kreditkartendaten. Weitere Informationen
NET::ERR_CERT_REVOKED"
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 04, 2019, 07:05:11 PM
They forgot to update their certificate.

You should be able to visit the site by using Firefox.

Someone should send them a mail, telling them their certificate has expired.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 04, 2019, 07:49:50 PM
Too much gets lost when I try to make a gif so link to previous animation
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif
(https://media.giphy.com/media/LSv89KK1niE9QFJW08/giphy.gif)
try zooming in on that
and a straight temp. animation from mercator, I play this at 200ms and zoom to 170%
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20190401/20190613/1/1
that's not too bad, it shows the ice forced against Ellesmere as it moves through Nares and some impression of just how much Atlantic water is forcing it's way through beneath the ice, given the huge displacement of Baffins existing ice cover. Most of Baffin/Arctic ice seems to be making it's way into Hudson, I guess the fresh melt/discharge waters are too, so a prolonged winter and cool summer for the bay.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 05, 2019, 09:24:34 PM
The salinity gif
(https://media.giphy.com/media/VcwTcA6uNAugRExH1m/giphy.gif)
There's more than one way to read this but my take is as stated above, Atlantic waters are now moving at depth down the west coast of Greenland speeding the melt of every glacier sitting in a deep fjord.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 05, 2019, 09:41:54 PM
Atlantic waters are now moving at depth down the west coast of Greenland

John, i've seen that before. Do you have the impression it increased? And if so, is Baffin Bay also Atlantifying?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 06, 2019, 12:56:22 AM
" Do you have the impression it increased?" Yes but by how much and whether it's temporary IDK??
" And if so, is Baffin Bay also Atlantifying?" Not sure if I'd call it that, the Atlantic water [from the north] such as it is will be diluted by meltwater from Greenland, so less saline nearer neutral kinetically and either cooling Hudson or the N.Atlantic. From the south the Irminger current will keep grinding on but it too will, probably, be held in check by increased flow from the north.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 06, 2019, 06:43:55 AM
Thanks for your opinion, John.

Let's keep that observed. ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on June 09, 2019, 03:32:32 AM
The Coriolis effect causes water masses to turn to the right or go northwards on the west coast of Greenland or southwards on the east coast of Canada. The same effect works in narrow passages like the Nares strait. When water masses interact, eddies are the result.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 09, 2019, 01:34:47 PM
The Coriolis effect causes water masses to turn to the right or go northwards on the west coast of Greenland or southwards on the east coast of Canada. The same effect works in narrow passages like the Nares strait. When water masses interact, eddies are the result.
and yet there's a deep current of Atlantic water that flows down the Greenland side, I understand this only by assuming that it retains some of the inertia that carried it eastwards to eventually pass between Iceland and Norway, Arctic waters lack that momentum and pass through on the Ellesmere side.
The image and first link are both at 100m., I'm assuming again, the higher salinity in the image as a proxy for Atlantic waters and the temp. anomaly against Greenland in north Baffin the same. 
(https://puu.sh/DDDrx/ba77c9bea4.jpg)
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/20190618/map/3/3/3#4/55.60/-102.44
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/20190618/map/3/11/1#3/52.75/-105.91
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 11, 2019, 04:17:15 PM
I'm thinking that Beaufort has become a killing zone for any myi that makes it past the garlic press, so given the apparent vorticity taking place there I looked at whats going on at depth in the mercator model 300m salinity
(https://media.giphy.com/media/W2hsezTdFdgAN5a96f/giphy.gif)
oops pressed post instead of preview,
What I think is happening is that as the surface ice/water is being pushed away by winds and the surface thrust of Amundsen tides, deeper water is being drawn into both Mclure and Amundsen, this, i think, is Atlantic waters which have been drawn along the shelf and being very kinetically uncormfortable is leading to extreme vorticity which reaches to the surface then gets caught in the gyre and moves west.
(https://media.giphy.com/media/TLgclNwSkj453cUzRl/giphy.gif)
Hycom sea ice thickness above
and here (https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2558.0;attach=122598) is A-Teams latest Ascat, which if anything looks worse than the models.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 11, 2019, 09:27:22 PM
Would it be possible to have this for the 0m salinity too?
At this time of year 0m salinity probably says more about bottom melt than ocean currents. I find it difficult to interpret.
Here is an update to mercator 34m salinity and worldview terra modis(high contrast), jun1-10.
Also a closer look at the area north of Svalbard using worldview aqua modis, jun1-11, default and very high contrast to show movement of multiple fine fractures.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 11, 2019, 09:42:21 PM
Update on whoi itp110 showing location, temperature, salinity and density (clockwise). Probably best viewed full screen.
@Pragma, the 'holes' in the profile are normally where the profiler stops for some reason, probably due to strong current, high speed drift, temporary fouling, turbulence etc
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: RoxTheGeologist on June 11, 2019, 11:04:04 PM
Mercator model, salinity 0m vs. 30m for the month of May.

Note that Mercator uses differing scales at different depths. Very annoying.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 12, 2019, 07:03:33 AM
Right! I'll include a scale next time.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 12, 2019, 12:39:16 PM
Ascat sep17-jun11. Still experimenting with the circular mask. The swaths move a little over time.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on June 12, 2019, 01:38:57 PM
Ascat sep17-jun11. Still experimenting with the circular mask. The swaths move a little over time.

Thanks for sharing that. Interesting that the ice at the N.Pole in September has all since departed via Fram. Gives a good sense of the life cycle.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 12, 2019, 01:41:34 PM
Gives a good sense of the life cycle this year.
For a longer term view please see 2010-2019 here https://forum.arctic-sea-ice.net/index.php/topic,2417.msg188990.html#msg188990
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on June 12, 2019, 02:04:33 PM
Thanks uniquorn. This is really amazing, and alarming - almost half the ice area that survived last season has been exported, mostly to the Atlantic Front, and some of it spread over the open water in the Beaufort. Hopefully it's a smaller fraction of last year's surviving volume. But still with most of the CAB covered by FYI, it's a setup for very sharp drops later in the season even with average weather.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 12, 2019, 04:44:46 PM
moon, thanks uniquorn bit amateur hour but have to start somewhere.
maybe we need a pack rotation thread just to keep yours and A-Teams work easily accesible?
Just to illustrate the vortice[?] action a little, temp., opening, salinity and ice strength from Hycom
(https://media.giphy.com/media/gfCUMUp3FF20OFbcdN/giphy.gif)

and looking at nullschool for about the same time no atmospheric cause afaics. https://earth.nullschool.net/#2019/06/07/0000Z/wind/surface/level/overlay=mean_sea_level_pressure/orthographic=-42.86,82.60,512/loc=-131.224,77.015
modified gif
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 13, 2019, 12:01:19 AM
Cyclone sitting over the beaufort for a few days might stir things up a bit more.

The low concentration area north of Svalbard starting to show again, even through the fairly constant export. Worldview aqua modis, high contrast and noaa bathymetry, jun11.
https://go.nasa.gov/2X4StFP
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Glen Koehler on June 13, 2019, 12:43:27 AM
RE #279   Are there full season versions of this video available from past years?  Would be very interesting for comparison.  I hope we have future updates of this video, it's the best thing I've seen for representing pack rotation and export.   

     Apart from the recent high temperature weather forecasts, it seems that low extent on the Pacific side; recent rapid and accelerating deterioration along the Siberian coast; and ice condition and mobility are the three big stories so far this melting season. 

     But I also see on Wipneus chart that Fram Strait export as measured by ice Extent was at normal level for May.  So I may be overeacting to the pack motion. 

    The video in Uniquorn's post shows the Nares Strait as a nasty leak shuttling ice out of the Lincoln Sea at a rapid pace.  Since Nares opening was early this year, that makes me think that overall export is an increased source of ice loss this year, and may be disproportionately removing what little 4 and 5 year old ice was left.

 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on June 13, 2019, 03:09:22 AM
    The video in Uniquorn's post shows the Nares Strait as a nasty leak shuttling ice out of the Lincoln Sea at a rapid pace.  Since Nares opening was early this year, that makes me think that overall export is an increased source of ice loss this year, and may be disproportionately removing what little 4 and 5 year old ice was left.

The Nares was never officially closed IMO.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Tor Bejnar on June 13, 2019, 04:46:16 AM
Who's to say if "Nares was closed (or not)" this year?  Certainly the Lincoln Sea Polynya arch prevented Arctic Ocean floes from entering the Strait for about a month.  We watched a 'race' in late February and March:
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 13, 2019, 03:34:18 PM
RE #279   Are there full season versions of this video available from past years?
please see 2010-2019 here https://forum.arctic-sea-ice.net/index.php/topic,2417.msg188990.html#msg188990
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 16, 2019, 11:25:35 PM
Update on the whoi itp buoys. https://www.whoi.edu/page.do?pid=163197
Incomplete profiles on itp89, 107 and 109 but all are still reporting location and internal buoy temperatures.
103 showing significantly different drift track to 104 and 105 since it drifted into shallower water. 104 and 105 still drifting north against the annual ice drift.
110 showing peaks of warmer water at 50-100m recently. The second animation is from may30-jun16.(longer animation above in post276)

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 17, 2019, 08:40:46 PM
whoi itp110 temperatures at 68-90m(dbar) for jun17 and approximate location jun16. It appears to be tethered to the arrow shaped floe, centre. https://go.nasa.gov/2MQS4CN

%year day pressure(dbar) temperature(C) salinity oxygen(umol/kg)
2019  168.03528   68   -0.0313   29.9886  346.8176
2019  168.03517   70    0.0957   30.2463  344.5711
2019  168.03508   72    0.0838   30.3616  343.0742
2019  168.03496   74    0.0633   30.4521  341.0866
2019  168.03486   76    0.0612   30.5492  338.5854
2019  168.03477   78    0.0888   30.6184  335.9899
2019  168.03467   80    0.1292   30.7162  333.2428
2019  168.03457   82    0.0466   30.8086  330.7020
2019  168.03448   84    0.0430   30.8697  327.7918
2019  168.03438   86    0.0982   30.9570  323.8962
2019  168.03427   88    0.0575   31.0426  320.0219
2019  168.03417   90   -0.0068   31.0948  316.5251

%year day longitude(E+) latitude(N+)
2019  167.70905  -143.6745  74.3031

edit: added itp110 temperature profile, 0-200m
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 18, 2019, 12:47:21 PM
Lucky to have a polarview sentinel1 image from jun17 of the itp110 floe. I think the buoy is attached somewhere bottom right of the triangular floe.
edit:Cross checking with the polarview lat/long grid, which is probably more accurate, itp110 may be a touch south east of the triangular floe. See third image.
2019  168.66721  -143.8305  74.2868
2019  168.68769  -143.8273  74.2863
2019  168.70888  -143.8237  74.2858
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on June 18, 2019, 01:12:40 PM
Both the temperature and salinity increased in the upper 30 meters at buoy 110 with the passage of the tight cyclone. Based on the graphs, the most likely correct interpretation is that the warm summer water layer located between 50m and 125m depth was partially mixed with the cold fresh upper water layer by the cyclone.

Needless to say, this situation will increase the bottom melting rate. The release of that stored heat in early to mid June appears to be a worst case situation for the sea ice. Perhaps cool weather will offset some of the damage to the ice, but it does not look good.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 18, 2019, 01:29:53 PM
Thanks FOoW. I should know to never post temps without salinity ;)

Wondering if all these cyclones are affecting the gyre, here is mercator(model) current at 34m, jan1-jun17, ~16days/sec
@johnm33 I see how the amundsen gulf could be seen as the 'gyre pump' here. Looks like it can't make it's mind up though.
forgot scale
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 18, 2019, 02:27:33 PM
Gyre pump, yes what I think would be a more 'natural' circulation would be Pacific waters driving along the coast/shelf towards Amundsen and then being pumped out in a more northerly direction generating lots of turbulence along the sheer line of the two currents. The Pacific water though flowing over/through the shallow strait doesn't seem to have the power to move according to it's own inertia but gets forced every which way according to the prevailing atmospherics and temporary underlying currents. So when it does flow towards Amundsen it disrupts Amundsens drawing in of Atlantic water at depth, the surface water being the easiest fraction to shift, then the highs/lows move around and back to square one.
hope that makes sense.
 Surprised me to see the to and fro above Santa Anna trough
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 18, 2019, 11:43:16 PM
Possibility of another injection of warm salty water north of Greenland with the upcoming weather.
Mercator(model) salinity 34m jan1-jun16
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 19, 2019, 11:51:55 PM
Close up of the nonsense crack, jun1-18, heavy contrast. Note the fine fractures to the north and the floes are fracturing further with some melting. (It is the season ;) ) Ile Borden lower left.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 20, 2019, 12:09:46 PM
Whoi itp109 and 110 are currently quite close together. Unfortunately 109 stopped sending profiles on dec15 but still sends a status report including location, temperature and battery voltage. Here they are roughly located on worldview terra modis today with their internal temperature chart. https://go.nasa.gov/2IVqnnn
109 buried in thick snow or surface ice?
Note that 110 hit 12.875C today despite windy ecmwf air temps of 0C. Must be sunny there today.
ITP110
Last buoy status on 2019/6/20 3047 UTC : temperature = 12.875 °C
Last position on 2019/6/20 3047 UTC : 74.1261° N, 143.3538° W
https://www.whoi.edu/page.do?pid=163197
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: prokaryotes on June 20, 2019, 03:01:55 PM
Possibility of another injection of warm salty water north of Greenland with the upcoming weather.
Mercator(model) salinity 34m jan1-jun16
Are people aware that higher salt content affect the stability zone of subsea permafrost deposits?

Made a post yesterday New Mechanism for Methane Hydrate Dissociation Discovered http://climatestate.com/2019/06/19/new-mechanism-for-methane-hydrate-dissociation/

Evaporation in the Arctic, historically been low due to the lower temperatures there, but with amplifications up there, likely a profound uptake in rains too from permafrost thaw, there is the question how the Arctic Water Cycle (AWC) will contribute to saltiness as well.

Are there ESAS region specific salt buoys? 

Update, googled a bit more..

Seven Years of SMOS Sea Surface Salinity at High Latitudes: Variability in Arctic and Sub-Arctic Regions https://www.mdpi.com/2072-4292/10/11/1772/htm

The Potential and Challenges of Using Soil Moisture Active Passive (SMAP) Sea Surface Salinity to Monitor Arctic Ocean Freshwater Changes https://www.mdpi.com/2072-4292/10/6/869/htm

Stability of the arctic halocline: a new indicator of arctic climate change https://iopscience.iop.org/article/10.1088/1748-9326/aaec1e/meta

Quote
A reduction in upward oceanic heat flux. This reduction in heat flux is due to increased precipitation that leads to fresher ocean surface waters and, hence, to more stable stratification of the upper Arctic Ocean. This stratification results in cooling of the ocean surface and warming of deeper ocean layers.
https://www.jstor.org/stable/26542658?seq=1#page_scan_tab_contents
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 21, 2019, 01:47:56 PM
Both the temperature and salinity increased in the upper 30 meters at buoy 110 with the passage of the tight cyclone.
itp110 update. It looks like the profiler couldn't move above 200m depth during the cyclone. The algo making the charts doesn't cope too well with the lack of data. Likely due to high drift speed.
location, temp, salinity, density, 50 days to jun21. click to run.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 22, 2019, 11:40:52 AM
30m 100m Mercator model, 01.06 to 21.06.

Atlantic waters are close to penetrating the Beauford Gyre.

(Thank you Uniquorn for the correction)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 22, 2019, 03:07:54 PM
That looks like 92m salinity. jun16 shown here with noaa bathymetry.
edit: chukchi plateau keeping most of the atlantic water away for now,
 unless you mean along the CAA
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: TeaPotty on June 22, 2019, 06:05:20 PM
30m 100m Mercator model, 01.06 to 21.06.

Atlantic waters are close to penetrating the Beauford Gyre.

(Thank you Uniquorn for the correction)

Hey b_lumenkraft, do you have a link to that animated arctic SST map you posted?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 22, 2019, 06:36:54 PM
Hey b_lumenkraft, do you have a link to that animated arctic SST map you posted?

That's salinity though, but sure! :)

http://bulletin.mercator-ocean.fr/en/PSY4/animation
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on June 22, 2019, 09:17:25 PM
That salty Atlantic water cools and sinks at the 300m level. The water doesn't penetrate the Beaufort gyre, but it does mix at depth with the cold fresher water that exits the gyre  and slowly moves towards the Fram strait at depths below 300m.

http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20190101/20190621/2/4

The sea bottom topography of the Arctic ocean and seas plays a key part in controlling the transport of salinity and heat in Arctic waters.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 22, 2019, 09:44:26 PM
Thanks, FOOW.

I guess i need to look more at these things. Never noticed it spins counterclockwise in this depth.

Here is the linked data as a GIF, speed up.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 22, 2019, 10:13:10 PM
thankfully it doesn't (yet). Mercator salinity 318m, jan1-jun21, 32days/sec. (not optimised)
Maybe an ezgif optimisation problem or an accidental reverse?
Still looking forward to more dates on your animations ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 22, 2019, 10:19:12 PM
I'm very confused right now.  ???

Kinda late here, will check tomorrow what's the problem with ezgif.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on June 23, 2019, 04:31:39 AM
That part of the ocean is confusing. There are 2 major factors to consider. One is the Coriolis effect. Pacific water entering the Arctic from the Bering strait tends to turn right, thanks to the Coriolis effect which is related to the conservation of angular momentum and the vorticity of water masses. Fresh water from Siberian rivers tends to hug the Siberian shores if it is moving counterclockwise. Likewise, incoming salty Atlantic water tends to hug the Siberian continental shelf.

It all turns into a spinning mess when the waters meet in the Chukchi sea. Note that the Alaska coastal current carrying Pacific water is moving in the opposite direction from the water and ice in the Beaufort gyre. When the Beaufort high is intense there is no ACC. Warm salty water from the Atlantic layer upwells along the shelf margin when the easterly winds are strong and persistent, often in the month of May. The ACC returns, typically this time of year, when the easterly winds die down near the coast.

And that's not all. This is also a part of the Arctic where water "densifies" and sinks to considerable depths. So it's no wonder the animations are confusing you.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on June 23, 2019, 08:33:30 AM
Thanks so much, FOOW! I bet this post is not only useful for me. :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 26, 2019, 04:02:37 PM
update on whoi itp110. Only 3 or 4 floes away from open water now. No surprises in the charts yet. Perhaps the temperatures above 80m depth are starting to rise a little. The profiler is struggling to move from depth today probably due to high drift speed. https://www.whoi.edu/page.do?pid=163197
animation of temp/salinity, day158-177.(jun7-26)
whoi itp110 profile, jun26
worldview terra modis approximate location, jun19-26
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 27, 2019, 01:48:03 PM
Prompted by Brigantine's post in the buoys thread I finally got around to running the numbers on whoi itp103. A lot of data as the profiler does 2 or 3 0-250m runs in between the 0-800m. Only showing 0-250, both up and down, in the animation below and no attempt to match the data with location. Some interesting turbulence here and there.
Interesting too that itp103 drift track roughly replicates the ice lift off from the caa.
whoi itp103 location, internal temperature, drift speed and profile for comparison. https://www.whoi.edu/page.do?pid=163356
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 27, 2019, 03:32:59 PM
mercator sea temperature 0m jun1-26, laptev-kara
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 27, 2019, 10:04:12 PM
whoi itp104 temperature and salinity, 0-250m, up to jun27.
whoi itp104 location/profile, jun27 for comparison   https://www.whoi.edu/page.do?pid=163376
Tends to confirm mercator model increase in salinity 0-50m as the buoy heads further north
Why not cane the computer while it's super hot?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 27, 2019, 10:54:45 PM
caa-cab crack, jun24-27 https://go.nasa.gov/31XrAmH
unihamburg amsr2-uhh apr29-jun26
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 28, 2019, 09:51:53 AM
Maybe something maybe nothing, I was looking at hycom beaufort ice strength gif, towards the end the ice appears to change state and is no longer able to sustain cracks, that is evidence of internal waves.
(https://media.giphy.com/media/SwfO6OlQvHxywZ3SVv/giphy.gif)
and looking at A.H.s (https://forum.arctic-sea-ice.net/index.php/topic,176.msg208819.html#msg208819) most recent gifs on the Nares thread suggests the same
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 28, 2019, 01:05:50 PM
https://en.wikipedia.org/wiki/Internal_wave
Thanks. Mostly floes up to 80N. Fine fractures further north. Ice with, apparently, little compressive strength. Last year looks similar though
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength_nowcast_anim365d.gif
Quote
Internal waves are gravity waves that oscillate within a fluid medium, rather than on its surface.[1] To exist, the fluid must be stratified: the density must change (continuously or discontinuously) with depth/height due to changes, for example, in temperature and/or salinity. If the density changes over a small vertical distance (as in the case of the thermocline in lakes and oceans or an atmospheric inversion), the waves propagate horizontally like surface waves, but do so at slower speeds as determined by the density difference of the fluid below and above the interface. If the density changes continuously, the waves can propagate vertically as well as horizontally through the fluid.
worldview aqua modis jun27, heavy contrast (click for default)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 28, 2019, 01:18:44 PM
While it's all set up here is whoi itp105 temp/salinity 0-250m  https://www.whoi.edu/page.do?pid=163456
edit:wasn't expecting that temperature spike, though I see it on the profile now.. ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 28, 2019, 03:15:22 PM
update on whoi itp110. https://www.whoi.edu/page.do?pid=163197
worldview image of local area https://go.nasa.gov/31VURyl
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 28, 2019, 03:31:22 PM
whoi itp109 starting to show some temperature change. https://www.whoi.edu/page.do?pid=163196
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on June 29, 2019, 01:04:37 AM
Uniquorn, I was looking at itp110 data for their SAMI which measures pCO2 and it appears several things have happened over the last couple weeks as the itp bouy switched direction . There was some warm pacific summer water that is the red colors on the temp/salinity contours,  the pCO2 increased as would be expected with an inflow of pacific water, the salinity jumped at the depth of the SAMI and there is a huge shift in PAR. Photo Active Radiation
https://www.researchgate.net/post/Can_I_convert_PAR_photo_active_radiation_value_of_micro_mole_M2_S_to_Solar_radiation_in_Watt_m22

So even though the bouy hasn't hit open water a very large jump in solar radiation has already occurred.
https://www.whoi.edu/page.do?pid=163197
Here is the SAMI info for itp 110

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 29, 2019, 10:38:06 AM
Thanks Bruce Steele. The SAMI is mounted at 6m depth.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on June 29, 2019, 05:04:35 PM
I looked around for more info on PAR ,interested in what to expect at various depths. I found this graph of PAR values in the Arabian Sea.

https://www.hindawi.com/journals/ijocean/2014/279412/fig3/

I made a mistake about changes in salinity , sorry. I am interested in these PAR measurements because they can be converted to watts per meter and so reflect a value for insolation. I am suprised  that the PAR values at 6 meters under broken ice is as high as it is and seems comparable to values in the Arabian Sea.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 29, 2019, 09:22:25 PM
no prob. I'd be grateful for anything 'plain english' you can find. The constant 6m temperature chart is already a big step forward :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 30, 2019, 01:39:15 PM
update on the shear fractures north of fjl extending beyond 86N. Worldview aqua modis, jun29-30, heavy contrast. click to run. Default here https://go.nasa.gov/2XaAR7d
Looks different in polarview sentinel1 but the polynyas are clearly visible.
Detected also on unihamburg amsr2-uhh, jun29, default and heavy contrast.
added piomas jun15 for good measure
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on June 30, 2019, 02:46:00 PM
Due to ice drift from the CAB, the ice north of FJI and Svalbard is in remarkably better shape then years past. It will be interesting to see where the ice edge is at the end of the melt season. I believe this region of the Arctic is key to how close we end up to the 2012 minimum.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 30, 2019, 02:56:09 PM
I think the ice north of fjl is thinner than most previous years largely due to the rapid southerly drift and fram export causing fracture and refreeze over the last freezing season and this melting season.

Here is a look at mercator sea surface height, sea temperature and salinity, pacific side, 0m, mar19-jun29
missing 0430 ssh and 0630 ssh is a forecast, oh well...
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 30, 2019, 08:26:59 PM
I was thinking about Chukchi/Ess, theres a new moon building up the tides coming through the strait, and developing lows just in/out of the Arctic, given that any water making the journey is probably energetically tuned to 10deg further south, so 1/6 further from the polar axis, when it arrives it will, if my guess is good, add turbulence wherever waves form, so could do a lot of damage on the shelf. Once it drops into the deep eddies will form and damage the ice further in, if  there were no poweful lows on the Atlantic side my guess would be it flows west but since it looks like increased flow in from the Atlantic is all I expect is an acceleration of flow out through Fram/Nares/Caa, if it's mainly the latter that will draw the Pacific water towards it and do a lot of damage there in a couple of weeks time. As it stands it looks like ESS gets hammered.
most recent amsr2, 02:07 nullschool
(https://media.giphy.com/media/dycinaOeCylhNPdlWY/giphy.gif)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on June 30, 2019, 10:15:01 PM
I found this SAMI from completed ITP missions. Itp 69 included a SAMI and a temperature chart.
The SAMI didn't work for long but the temperatures never rose to the -.8 that itp 110 is currently reading.

https://www.whoi.edu/page.do?pid=163476
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 30, 2019, 11:13:40 PM
@Bruce, looking at the drift track itp69 followed the 80N line so it probably wouldn't have been close to open water during time the sami was working. That 50m warm layer is quite thick on the profile in 2013/14 though.

@John, itp107 is on the edge of the chukchi plateau. The profiler is hardly moving but I grabbed what I could from it, between 180-300m, over the last 86 days. If the data means anything it's having a rough time of it. The microcat and sami, mounted at 6m depth, are still working and both show a ~0.2C rise over the last 20 days. Also a big spike on day 490.
Worldview terra modis view of approximate location jun30 https://go.nasa.gov/2X8dkny
whoi itp107 drift track, microcat and sami, jun30ish
whoi itp107 location, temperature and salinity, day96-181(jun30) click to run

edit: Could the sami readings be used as a proxy for ice thickness? I suppose not with a spike like that. Thinking about it, the profiler is probably being dragged along the ocean floor. In a few more days it might reach deeper water.
edit2: Temperature spike was roughly when it hit the chukchi plateau on day125 (490-365)
2019  125.00054  -154.4100  76.4394
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on July 01, 2019, 02:01:17 AM
107, the bathymetry thereabouts is extremely complex, it's clear we have increased flows coming in from the Pacific, it's likely that a significant fraction of that water is falling into the deep east of the plateau, I guess that general shifts in the whole body of water creates complex tornado like vortices with shear zones at salinity thresholds, akin to refraction, whilst the vortices seek out the deepest 'holes' ... expend their energy and die/to achieve equilibrium. That in contrast to the relative calm on the surface which anchors the bouy somewhat like a reverse sea anchor.
(https://puu.sh/DN1jL/e352eba6af.jpg)
microcat and sami I'm gonna run with Bruces take until i think I  have any insight that might help.
ice thickness, Until the ice begins to react in some logically transparent way I have to believe it's a complex mix of plates with no keel and lets say bottles which are mostly keel, the big plates transition to bottles and the shrinking bottles transition to small plates, and they're all constrained by their surroundings until they're not. We may see them sorted by the passing waves. So I'd guess there's something to be learned about what near surface/surface waters are running through the area  from the bouys, something else to think about.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on July 01, 2019, 03:27:56 AM
That summer water layer is a key to understanding why the Beaufort sea has turned into a killing zone for thick ice rotated in from the CAA. Over the past several decades the amount of heat stored over the winter in the summer layer has increased substantially. There's a positive feedback now with more open water in late spring and more solar heat taken up by open water.

All that shattered and dispersed ice that we see now in the Beaufort sea is going to melt out quickly under the combined effects of sunshine, open water that took up early heat and heat stored over winter in the summer water layer.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Pragma on July 01, 2019, 07:11:06 AM
1.3 m ~ 4.4 feet. I took a lot of grief last night for suggesting the "surge" through the Strait would be maintained to the ice front.

I confess to being uncertain as to what happens dynamically at the water / ice interface but I'm not confident that anyone here thus far has the answer to that.

I'm sticking with my gut here and suggesting that there is a real possibility that a LOT of (warm) water goes over the top.of the ice edge.
Rich:

For the sake of everyone on the forum, would you please look up the definition of the word "swell" in the context of "ocean swell"?

When a chart or met forecast talks about "5 foot seas", they mean 5 foot waves.
When someone refers to 5 foot swells, they also mean 5 foot waves.

Swells are not surges. Swells are waves. They are up and down motions of a body of water, so a 5 foot swell has a peak to trough height of 5 feet, or plus and minus 2.5 feet from the average water height. The term "swell" typically applies to long slow waves. In other words, a long wavelength, or the distance between successive peaks. They are associated with large bodies of water, usually oceans. Shorter wavelength waves are referred to as chop or choppy waves.

You did not get grief last night as much as you had a bunch of knowledgeable people trying to explain that you were misinterpreting charts and confusing terms, among other things.

It appears that those sincere efforts have been in vain.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 08:14:46 AM
Pragma...I'm happy to continue the discussion here.

I understand the distinction between a swell (wave) and a surge. Nevertheless, I persist. Why is that?

In the event of a surge, how would the software which is informing of us a "swell" differentiate a surge from a swell? To assume that there is sufficient intelligence to make that differentiation would be a bad assumption on my part.

At this point in time, I'm going to assume that characterization of swell is accurate. My gut understanding is that the volume of water coming through the Strait SO FAR is insufficient to sustain a surge all the way to the ice front.

But this is not a one day phenomena and there are many factors to consider in making a judgement as to the potential for a genuine surge.

1) The long "fetch" of the tail winds in the Pacific.

2) The duration , consistency and strength of the wind field.

3) The wind field within the Arctic which is concentrating any buildup of water on the Asian side of the Arctic. It's blowing from the Beaufort toward the ESS.

4) The uncertainty of what happens at the ocean / ice interface.

The conventional wisdom of the forum is that a surge is impossible. I'm trying to explore the constraints of that assumption.

If you want to debunk the possibility of a surge, there should be some math which suggests the volume of water required to produce one in a given location and demonstrating that the current environment doesn't have the possibility of producing it

5 people on ASIF saying that they don't consider it possible is hardly scientific, no?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on July 01, 2019, 08:35:26 AM
Pragma...I'm happy to continue the discussion here.

I understand the distinction between a swell (wave) and a surge. Nevertheless, I persist. Why is that?

In the event of a surge, how would the software which is informing of us a "swell" differentiate a surge from a swell? To assume that there is sufficient intelligence to make that differentiation would be a bad assumption on my part.

Why would it make any difference if it is a surge and not a swell? Surges are very common and do not in any way imply lateral movement of water. Surges are created by pressure differences, when pressure goes down, the ocean surface goes up, but there is no lateral movement of water!


At this point in time, I'm going to assume that characterization of swell is accurate. My gut understanding is that the volume of water coming through the Strait SO FAR is insufficient to sustain a surge all the way to the ice front.


There is no volume of water coming through the Bering Strait connected to any surge. Surges are not lateral movements of water, but pressure-induced vertical movements of water.


But this is not a one day phenomena and there are many factors to consider in making a judgement as to the potential for a genuine surge.

1) The long "fetch" of the tail winds in the Pacific.

2) The duration , consistency and strength of the wind field.

3) The wind field within the Arctic which is concentrating any buildup of water on the Asian side of the Arctic. It's blowing from the Beaufort toward the ESS.

4) The uncertainty of what happens at the ocean / ice interface.


There is no uncertainty here. Surges and waves are an everyday occurrence at the ice edge, and never does the water flow over the ice. Never. The ice stays on top and moves with the waves and surges and what have you.


The conventional wisdom of the forum is that a surge is impossible. I'm trying to explore the constraints of that assumption.


The conventional wisdom is that surges are common and mostly harmless.

"Trying to explore the constraints of that assumption"  ... please!

If you want to debunk the possibility of a surge, there should be some math which suggests the volume of water required to produce one in a given location and demonstrating that the current environment doesn't have the possibility of producing it

5 people on ASIF saying that they don't consider it possible is hardly scientific, no?

What volume of water? Who is denying the possibility of surges? Your claims are:

1) A possible storm surge coming in from the Pacific would be 1 m high entering the Bering strait and somehow come out on the other side twice as tall.

2) That his surge will maintain the 2 meters for the next 400 kilometers until it meets the ice.

3) That this surge will then inundate the ice for a considerable distance.

4) Underlying is an unstated assumption that a surge involves the lateral movement of water. It does not.

All of this is wrong - point 1 because this is not a lateral movement of water, point 2 because even if it did gain an extra 1 m it would lose that very quickly, 3 is wrong because that is not what happens when waves meet ice, and 4 is wrong because that is simply not how things work!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 01, 2019, 08:36:10 AM
Rich, I know you mean well and you have a good point regarding the importance of the long fetch south wind from the Bering Strait to the ice front. However, that cannot justify a scientific error that you seem to be making (or I am misinterpreting). A mass of water, be it a surge or a swell, cannot overtop and drown sea ice. Ice floats, it acts like a buoy, it bobs up and down the swell or climbs on top of the surge. I am aware of several effects that are possible with surges/swell/waves (warning - layman's terms):
* Tall frequent waves spraying or hitting the ice edge - the first few meters of a floe. Remember that most floes are hundreds of meters or kilometers across. Small marginal floes can be obliterated by this wave action.
* Deep swells making the ice bob so hard that it breaks, this mainly affects large floes as the swell lifts just part of the floe. The flip side is that the ice attenuates such swells, and they can't go very deep into the pack.
* Surge/wind pushing the ice so that it compacts. This shows up as drops in extent, but in the longer term may be better for the ice as it becomes more protected.

I am not aware of a phenomenon whereby a surge overtops a field of ice. Your experience from Miami gives you a false intuition, as the surge in the Arctic is a slow moving thing rather than a hurricane-driven monstrosity, and the ice is a floating and mobile object rather than a stationary coastal installation.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 08:40:01 AM
This conversation reminds of an exchange in the Princess Bride, a movie full of memorable exchanges....

(as they are entering the Fire Swamp)

Buttercup: "We'll never survive"

Wesley: "Nonsense. You're just saying that because no one ever has (survived the Fire Swamp)".
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 09:12:16 AM
Rich, I know you mean well and you have a good point regarding the importance of the long fetch south wind from the Bering Strait to the ice front. However, that cannot justify a scientific error that you seem to be making (or I am misinterpreting). A mass of water, be it a surge or a swell, cannot overtop and drown sea ice. Ice floats, it acts like a buoy, it bobs up and down the swell or climbs on top of the surge. I am aware of several effects that are possible with surges/swell/waves (warning - layman's terms):
* Tall frequent waves spraying or hitting the ice edge - the first few meters of a floe. Remember that most floes are hundreds of meters or kilometers across. Small marginal floes can be obliterated by this wave action.
* Deep swells making the ice bob so hard that it breaks, this mainly affects large floes as the swell lifts just part of the floe. The flip side is that the ice attenuates such swells, and they can't go very deep into the pack.
* Surge/wind pushing the ice so that it compacts. This shows up as drops in extent, but in the longer term may be better for the ice as it becomes more protected.

I am not aware of a phenomenon whereby a surge overtops a field of ice. Your experience from Miami gives you a false intuition, as the surge in the Arctic is a slow moving thing rather than a hurricane-driven monstrosity, and the ice is a floating and mobile object rather than a stationary coastal installation.

Hi Oren,

I'm not so dense as to miss the point you are making. Yes, of course ice floats on water and I see the conventional wisdom that is being pushed in my direction.

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.

The incoming water will be much warmer than the Arctic water it encounters and less dense on that factor. It will be saltier making, a factor making it more dense. Net relative density...uncertain.


So let's say the initial waves hitting the coastal ice have some splashes going over the ice edge. Easy to imagine.

The incoming water travels a few meters over the ice surface until it finds a gap and goes down to meet the existing water below. Also easy to imagine.

What happens next is key. Is the incoming water dense enough to displace existing water and force water underneath the ice? Or is the incoming water light enough to float on top of the existing water?

In the scenario where the incoming water is either going under the itself or forcing the existing freshwater under the ice, then of course the ice pack will float higher with the influx of new water.

In the scenario where the incoming is not dense enough to force itself or the existing water under the ice, then the assumption of the ice rising with the influx of water can be questioned.

The salt content of the Pacific is generally much less than the Atlantic. I'm not sure how obvious it is that the water will sink upon arrival. This looks like the thread where one is most likely to get an educated guess.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 01, 2019, 09:36:11 AM
What happens next is key. Is the incoming water dense enough to displace existing water and force water underneath the ice? Or is the incoming water light enough to float on top of the existing water?

In the scenario where the incoming water is either going under the itself or forcing the existing freshwater under the ice, then of course the ice pack will float higher with the influx of new water.

In the scenario where the incoming is not dense enough to force itself or the existing water under the ice, then the assumption of the ice rising with the influx of water can be questioned.
Whether the incoming water floats over the existing water makes no matter. In both cases the ice will float on top of both. You don't need to force the water under the ice - the ice will rise above any water you stick in its way.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on July 01, 2019, 09:50:16 AM

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 10:08:38 AM

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.

Keep shouting. That's the key.

First of all, if you are right.... there is already warm water at the ocean ice interface in the Chuchki.

Second, the sensors as reported by Windy.com and reported in the melting season thread are showing a 0.5 knot current speed heading into the Arctic. Surely, wind can influence current and move water laterally.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Hopen Times on July 01, 2019, 10:17:21 AM
I am going a bit out of my comfort sone, but I will try to add a piece to the surge/swell/wave-hitting-the-ice discussion. I would like to say that a tidal wave is a kind of a surge, please correct me if am wrong here. If Rich is correct about his thoughts about surges flooding ice, then I think tidal waves should have the capacity to flood ice, at least in some spots. Tidal waves, needles to say, occur regularly, so it should be easy to find examples of tidal waves/surges flooding the ice.

Rich, you have a hypothesis that surges can flood ice, can you back it with observations?

I think you will have a hard time finding examples of flooded sea ice. My self, I have never seen, or never heard of, the ice be flooded by waves or surges and I have spent six winters on a smal island in the Barent Sea, surrounded by drift ice, spending a lot of time on the ice and watching the ice. 

I have a video that shows what happens to the ice when the tidal waves passes. 

https://youtu.be/YBTVJIH6En8 (https://youtu.be/YBTVJIH6En8)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on July 01, 2019, 10:37:19 AM

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.

Keep shouting. That's the key.

Well it seems such a fundamental thing to get wrong. Any literature about waves will tell you this, and I honestly thought that this was something that all adults knew.


First of all, if you are right.... there is already warm water at the ocean ice interface in the Chuchki.

Second, the sensors as reported by Windy.com and reported in the melting season thread are showing a 0.5 knot current speed heading into the Arctic. Surely, wind can influence current and move water laterally.

Wind does indeed influence current and does indeed move water laterally. Wind push is generally considered to constitute 1/3 of the driving force behind the Gulf Current. But this does not mean that waves move water laterally. They do not.

Waves are essentially pressure ridges - high pressure lifts the water up, and the pressure ridges propagate like ... like waves. (Edit: High pressure here indicates pressure within the wave-propagating medium, i.e. water. Not to be confused by the following discussion about the effects of air pressure on sea surface height).

Storm surges are caused by pressure differentials, each 10 hPa in pressure differential can lift/depress the ocean surface by roughly 10cm. So the water that rises inside the surge is being pushed up by water elsewhere, where pressure is higher. This of course implies some minor lateral movement, but each water molecule is perhaps shifted a few meters to one side or the other.

(A common analogy is the movement of electrons in a wire when alternating current is applied. The current flows at close to the speed of light, but the electrons are moving down the wire at a speed of a few cm per hour. It's the waves in the electric current that move very fast, but the electrons mostly just shuffle back and forth).

Of course, once a wave or a surge hits land, things start behaving very differently. A shelfing shore will push the wave upwards until it starts falling over (i.e. breakers) and the height increase may cause inundation (i.e. flooding). But even the huge tsunamis that drench whole coastlines are only waves that move water up and down, and it is the very large increase in sea surface that causes the eventual flooding and dissipation of the wave energy at the same time.

But we are not talking about anything like that here.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 11:05:07 AM
So, at this point I'm not pushing the idea the warm salty water molecule is heading for the ice front.

I'm on to the idea that wave is pushing the fresh warm water molecule currently at the Chuchki ice interface over the ice wall in front of it.

In the meantime, a 0.5 knot current is roughly 0.9 km / hr. traveling through an 82 km wide opening in the Strait.

I don't know the depth of the current. Does it extend to the floor of the strait or is it just a few meters deep. That would tell us how much 5-10C water is being added to the Arctic.

For each meter of depth, the current is adding ~ 82 * 0.9 / 1000 or ~ 0.075 km3 of water to the Arctic each hour. If we assume a 10m depth (just a guess), then that works out to 18.0 km3 per day of water moving laterally through the Strait into the Arctic.

Is that material or significant ? Perhaps not. It's just my response to your shouting that "THERE IS NO INCOMING WATER".

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 01, 2019, 11:16:49 AM
That reminds me. We haven't had a wave forecast for a long time.
windy ecmwf wam (wave) forecast, chukchi sea, junjul1-10 and today for the greenland sea
For big wave action on ice I'd recommend looking at the greenland sea at the moment.
https://www.windy.com/-Waves-waves?waves,75.453,33.750,3
@Hopen Times. Thanks for that lovely video.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on July 01, 2019, 11:26:21 AM
I'm on to the idea that wave is pushing the fresh warm water molecule currently at the Chuchki ice interface over the ice wall in front of it.

You really don't give up do you. But the lack of grammar and the spuriously introduced "ice wall" tells me that the batteries are running out.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Sterks on July 01, 2019, 11:38:07 AM

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.
A wave, swell, surge or  will transform the vertical movement energy into lateral movement as the incoming wave or surge reaches a shallower waters and ultimately the coast.

But that wont work with ice: no shallowing of the ocean, and no rigid boundary, just ice that floats like a buoy. That’s what’s confusing Rich, there are no breaking wave in this scenario
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: BenB on July 01, 2019, 12:32:00 PM
Re storm surge:

https://scied.ucar.edu/what-causes-storm-surge (https://scied.ucar.edu/what-causes-storm-surge)

Quote:

Wind piles up the water.

As winds swirl around a hurricane or tropical storm, seawater is pushed into a mound at the storm’s center. Faster wind is able to pile up more water. Because wind speed determines a hurricane’s category according to the Saffir-Simpson Scale, Category 4 and 5 storms are able to produce a larger mound of water than Category 1 and 2 storms. The mound of water isn’t noticeable out at sea, but as it approaches a coast, the impact is seen as storm surge flooding.

Low air pressure also plays a role.

At the center of a hurricane, air pressure is low. Low air pressure causes a slight bulge in the ocean, which adds to the mound of water that causes storm surge. Most of the water is piled up by wind, but about 5% of the mound is due to low air pressure.


I know this refers specifically to hurricanes, because that's when storm surge is the biggest problem, but I think the basic principles are the same for less powerful cyclones. Either way, like others I don't see how this is relevant to what is happening in the Bering Strait/Chukchi. For the water to pile up significantly, it really needs something to pile up against, which generally means land, or at least shallower water. The bathymetry of the Chukchi doesn't support that.

More relevantly, I've read that as a rule of thumb wind-generated surface ocean currents travel at about 3% of the wind speed. That would, in very round numbers, tie in with 20 knot winds generating a 0.5 knot current. A current of that magnitude brings quite a lot of relatively warm water into contact with the ice edge, but the impact will be incremental, and not a game-changer on its own.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 12:42:52 PM
I'm on to the idea that wave is pushing the fresh warm water molecule currently at the Chuchki ice interface over the ice wall in front of it.

You really don't give up do you. But the lack of grammar and the spuriously introduced "ice wall" tells me that the batteries are running out.

No, I don't, give up easily. Your resorting to ad hominem attacks suggests you're the one who is wearing out.

I like your initiative of breaking it down to a molecule by molecule basis.

What happens when the water on the edge of the ice / ocean interface rises? If there is a solid ice barrier (wall), the water level will rise until an open space and gravity force the water to move laterally into the ice pack.

Gravitational force and ice boundaries will dictate the lateral movement of the incoming water. It will move to the lowest point possible, but not through solid ice.

If gravity takes the incoming water to a location where there is already water present, then the density of the incoming water becomes relevant. If the incoming water is less dense (or equallly dense) than the water layer it comes into contact with, it will not mix. It will just sit stop the existing layer until enough water is added to let gravity do it's thing again.

If the water is not heavy enough to cause mixing, then the argument that the ice will rise is based upon what?

My argument can easily be killed by claiming that the incoming water is dense enough that it will definitely cause mixing. But no one is yet making that argument and so I persist until someone can stick a fork in my argument to my satisfaction.

You don't want people to give up w/o understanding, do you?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on July 01, 2019, 12:49:21 PM
What happens when the water on the edge of the ice / ocean interface rises? If there is a solid ice barrier (wall), the water level will rise until an open space and gravity force the water to move laterally into the ice pack.

The water rises and falls all the time, with waves and tides etc. There is no solid ice barrier or wall, just a bunch of floating floes.


Gravitational force and ice boundaries will dictate the lateral movement of the incoming water. It will move to the lowest point possible, but not through solid ice.
No it just floats under the ice.

If gravity takes the incoming water to a location where there is already water present, then the density of the incoming water becomes relevant. If the incoming water is less dense (or equallly dense) than the water layer it comes into contact with, it will not mix. It will just sit stop the existing layer until enough water is added to let gravity do it's thing again.

If the water is not heavy enough to cause mixing, then the argument that the ice will rise is based upon what?

My argument can easily be killed by claiming that the incoming water is dense enough that it will definitely cause mixing. But no one is yet making that argument and so I persist until someone can stick a fork in my argument to my satisfaction.

You don't want people to give up w/o understanding, do you?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on July 01, 2019, 12:52:06 PM
I just realised that I've been totally trolled! I've been well and truly duped into one of the stupidest discussion I've ever seen on this forum all the years I've been here.

I apologize and have hereby stopped writing on the subject.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on July 01, 2019, 01:04:21 PM
I have a video ...

This might be one of the most beautiful YouTube videos i've ever seen.

Thanks so much for sharing!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 01:04:32 PM
I just realised that I've been totally trolled! I've been well and truly duped into one of the stupidest discussion I've ever seen on this forum all the years I've been here.

I apologize and have hereby stopped writing on the subject.

I'm sorry, but this is only piece of the argument that I'm certain about. You weren't being trolled. I may be wrong and missing something very fundamental, but I'm not disingenuous.

You're efforts at mind-reading are a failure in this instance.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 01, 2019, 01:30:59 PM
107, the bathymetry thereabouts is extremely complex.
The profiler on itp107 started having serious problems moving after it turned north along the line of the chukchi plateau. Either it experienced a traumatic event, damaging the traction drive, or it is struggling with turbulent water combined with relatively high drift. Motor current is not peaking that high so maybe the traction wheel is slipping. Heading north again today so is probably bumping back over the same bit of sea bed.
Quote
Larger motor currents are observed at times of fast ice floe motion when larger wire angles develop and drag forces on the profiler are increased.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on July 01, 2019, 01:52:27 PM
Instead of making stuff up about winds and waves, you all might consider reading articles in the literature. You might start here to learn about what's happening in the Bering strait.
https://www.sciencedirect.com/science/article/pii/S0079661117302215

As to my earlier post in this thread, Frivolous points out elsewhere that the summer water layer may not interact with the surface layers. However, Ekman pumping and eddies in the Beaufort sea may bring some of that stored heat to the surface. Ekman pumping is important along the continental shelf margin of the Beaufort sea when high pressure is sustained and easterly winds blow for days. I'm not sure what's causing the apparent mixing now that buoy 110 is reporting.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 01, 2019, 02:46:10 PM
<>I'm not sure what's causing the apparent mixing now that buoy 110 is reporting.
It doesn't look like there is much mixing. At day180, the last complete profile yesterday, 7m-50m is warming up a bit and salinity has dropped. The profile contours don't display incomplete profiles very well (imho).
whoi itp110 temperature/salinity day158-180 and whoi profile contours, jul1
edit:struggled to upload files correctly
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: gerontocrat on July 01, 2019, 03:09:33 PM
Instead of making stuff up about winds and waves, you all might consider reading articles in the literature. You might start here to learn about what's happening in the Bering strait.
https://www.sciencedirect.com/science/article/pii/S0079661117302215

As to my earlier post in this thread, Frivolous points out elsewhere that the summer water layer may not interact with the surface layers. However, Ekman pumping and eddies in the Beaufort sea may bring some of that stored heat to the surface. Ekman pumping is important along the continental shelf margin of the Beaufort sea when high pressure is sustained and easterly winds blow for days. I'm not sure what's causing the apparent mixing now that buoy 110 is reporting.
I read it, and from it came away with:-
Quote
A seasonal warming trend in the strait proper in May and June (∼0.04 °C/yr) is reflected in a trend to earlier arrival (0.9 ± 0.8 days/yr) of waters warmer than 0 °C. Contrastingly, no significant trend is found in the time of cooling of the strait. 
If I read that right, I am surprised - the hotter sea not delaying the freeze date?

and:-
Quote
By separating the flow into portions driven by (a) the local wind and (b) a far-field (Pacific-Arctic “pressure-head”) forcing, we find the increase in the Bering Strait throughflow is primarily due to a strong increase in the far-field forcing, not changes in the wind.

so googling I found:- http://psc.apl.washington.edu/HLD/Bstrait/Woodgate_BeringStrait_ASOF_Apr2018Final.pdf

Which with a vast collection of graphs, maps etc tells you just about everything, and includes the message repeated in the sciencedirect.com article -

Quote
Finally we conclude that year-round in situ mooring are still the only currently viable way of obtaining accurate quantifications of the properties of the Pacific input to the Arctic.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: kassy on July 01, 2019, 03:23:47 PM
If I read that right, I am surprised - the hotter sea not delaying the freeze date?

Maybe the yellow label on the last map has got something to do with it?
Flux increases
Winter Freshening
Early Warming

The fresher waters (by extra melt) make freezing easier at the end. It will take time before the trend reaches the end of the season and other processes will mix things up before that.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: b_lumenkraft on July 01, 2019, 03:24:54 PM
On the slides, it says 20 days delayed cooling in 2016.

(last slide, bottom left)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on July 01, 2019, 04:39:34 PM
I just realised that I've been totally trolled! I've been well and truly duped into one of the stupidest discussion I've ever seen on this forum all the years I've been here.

I apologize and have hereby stopped writing on the subject.

I'm sorry, but this is only piece of the argument that I'm certain about. You weren't being trolled. I may be wrong and missing something very fundamental, but I'm not disingenuous.

You're efforts at mind-reading are a failure in this instance.

The fundamental piece you have been ignoring (not missing) is that ice floats on top of water.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on July 01, 2019, 05:03:32 PM
After a hard slog through this thread, I decided to pour myself a stiff drink. Dropped a couple of ice cubes in and damn if they did not sink to the bottom of my glass.  ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on July 01, 2019, 05:06:42 PM
After a hard slog through this thread, I decided to pour myself a stiff drink. Dropped a couple of ice cubes in and damn if they did not sink to the bottom of my glass.  ;)
Did you get a picture of that!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Pragma on July 01, 2019, 05:10:44 PM
After a hard slog through this thread, I decided to pour myself a stiff drink. Dropped a couple of ice cubes in and damn if they did not sink to the bottom of my glass.  ;)

It must have been light rum.

I prefer dark myself
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: BenB on July 01, 2019, 05:18:24 PM
After a hard slog through this thread, I decided to pour myself a stiff drink. Dropped a couple of ice cubes in and damn if they did not sink to the bottom of my glass.  ;)

But what would have happened if you had used whisky stones?  ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 01, 2019, 05:48:21 PM
There is a new sensor on the two ITP buoys that have a SAMI ( itp 110 and itp 107 ) . A SAMI measures pCO2 but attached with the SAMI at 6 meters is sensor that measures PAR . PAR is a measure of light intensity at a wavelength that plants and phytoplankton use. Both buoys show clearly that when the sunlight increases at 6 meters the water temperature increases also. The increase in water temperature is happening under the ice. I think we all knew  insolation caused heating but after watching these ITP buoys for years and years it is obvious now that the warming we see in the surface fresh water is coming from above ( the sun ) and not below , at least for buoys riding around in the
Beaufort Gyre . There is upwelling along the edges of the Gyre on the shelf  but these ITP buoys have lots of color spikes , glitches , that make spotting upwelling events difficult , difficult for me anyhow.
 
Rich , I think the amount of fresh water in the Beaufort, under the ice but also out at the margins even when the ice has melted , is very thick. A surface lens of cold fresh water exists everywhere those ITP buoys go so at some point the salty warmer water headed north through the Berring Straits hits that fresh water and sinks. When it sinks it takes its heat with it . The SST anomaly maps I think confuse us because they don't show us salinity and the salinity difference is what makes that warm Pacific water sink.
The Pacific water has to flow north because sea levels are higher in the Pacific than the Atlantic and when high tides and a Southerly windflow combine you get additional flow . Most of the water moves in the deepest channels and turns right , sinks and is entrained in the gyre under tens of meters of fresh water. The one thing that is a pretty big potential problem is that under certain cyclonic conditions the Beaufort Grye can reverse its spin and disgorge much of the water spinning around there. It has happened before and it will be amazing to watch if it happens again. I hope we have some ITP buoys working if and when the gyre relaxes. 
 
 
I think reading Woodgate on the processes of water movement the the Berring Straits is required reading. Too bad we don't have those buoy arrays still working .
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 01, 2019, 06:00:03 PM
FYI - I was able to iterate to the sought after gap in my understanding over in the Stupid Questions thread.

Sometimes there is knowledge that is common in a community that is relatively ubiquitous and the only way you can figure out how to get to the right understanding is kinda messy.

I'm happy to have learned something.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: jdallen on July 01, 2019, 07:16:31 PM

But we need to consider the properties of the incoming water and ask ourselves whether it will sink when it comes into contact with it's new surroundings.


THERE IS NO INCOMING WATER!

How often does this have to be repeated: A wave, a surge or a swell does not move water sideways! If a surge enters the Bering and continues into the Arctic, this does not imply ANY sideways movement of water.

A storm swell or surge through the Bering and continuing into the Arctic ocean does not bring any warm water with it. It's only the surface going up and down because of pressure differentials.

Keep shouting. That's the key.

First of all, if you are right.... there is already warm water at the ocean ice interface in the Chuchki.

Second, the sensors as reported by Windy.com and reported in the melting season thread are showing a 0.5 knot current speed heading into the Arctic. Surely, wind can influence current and move water laterally.

Bugs in my garden move faster.

Rich, you are intransigently ignoring both well understood properties of water and the responsiveness of the system, as well as demonstrating a fundamental lack of understanding of the Arctic as a system itself.

Your "how will water behave" question doesn't lead to some brilliant counterintuitive answer. It is nonsensical.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 01, 2019, 07:29:18 PM
back on topic please
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: RoxTheGeologist on July 01, 2019, 07:46:27 PM
After a hard slog through this thread, I decided to pour myself a stiff drink. Dropped a couple of ice cubes in and damn if they did not sink to the bottom of my glass.  ;)

Your drink needs a higher alcohol content.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: BenB on July 01, 2019, 08:51:19 PM
It feels a bit like we're talking at cross purposes here.

Can we agree that:

1. Water molecules in waves move in circles, which get smaller as you move deeper into the water. On a net basis, they neither move vertically or horizontally.

2. There is an average northward flow through the Bering Strait driven by the mechanisms described in Fish's link. This does result in water flowing into the Arctic, and can bring relative warmth.

3. Winds can drive surface currents, particularly if they are persistent. This also leads to horizontal movement of potentially warm or cold water.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on July 01, 2019, 11:23:53 PM
" turbulent water combined with relatively high drift." I agree, the surface is subject to very different movement so if the instruments act in any way like a sea anchor they will get caught up in deeper currents, the gyre against the plateau shelf for instance, and any 'waterfalls' coming off the plateau, twisting and snagging would seem difficult to avoid once in close.
(https://puu.sh/DNLRl/a7d69e5e3e.jpg)
(https://puu.sh/DNLNE/1717381eb1.jpg)
 edit: added images
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 04, 2019, 04:37:08 PM
>> Both buoys show clearly that when the sunlight increases at 6 meters the water temperature increases also. The increase in water temperature is happening under the ice.
The microcats also add further confirmation of that. Even itp104 and 105 further north and far from the ice edge show a somewhat smaller rise at 5m and 6m.
whoi itp103-110 microcat and sami data, jul4
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 06, 2019, 12:39:11 AM
ascat, medium contrast, day 160-185. The 3 or 4 floes below centre to the left of the pole hole have something of a survivor look about them. I'll try to track their history. A quick check and it's A-Teams stationary area here https://forum.arctic-sea-ice.net/index.php/topic,2558.msg209218.html#msg209218
Less movement, less fractures, cold area, better quality ice perhaps. Or it looks better because it doesn't move.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 06, 2019, 01:47:53 PM
They don't look like survivors on worldview aqua modis, jul5, high contrast. I think it is snow.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 06, 2019, 01:50:50 PM
A link to mercator 34m salinity animation with amsr2uhh overlay, mar21-jul4
https://forum.arctic-sea-ice.net/index.php/topic,2591.msg211134.html#msg211134
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 06, 2019, 05:42:58 PM
mercator(model) 0m salinity with uni-hamburg amsr2-uhh overlaid at 40%. Open water(blue) set to transparent. mar21-jul4.
glitch at the end is due to 4 mercator forecast days instead of analysis, will fix that for next time
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on July 06, 2019, 08:48:37 PM
There's so much to see there, most surprising is the reach and speed of generation of the pressure waves into the Arctic generated by surges from the Pacific.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 07, 2019, 05:44:12 PM
The PAR , photo active radiation, and water temperature readings on the ITP 110 buoy seem to go up or down in unison. The incoming radiation is constant 24 hrs. a day or very close to constant at those latitudes but clouds ,water turbidity , ice thickness or snow cover can reduce the amount of light reaching six meters. Most of the heat from solar radiation is taken up by top meter of seawater and mixed into the surface waters above the thermocline ( at about 50 meters on ITP 110 currently ) so it is interesting to me how quickly heat is mixed from surface heating on sunny days into 6 meters of water.
"In a body of water, infrared light can only reach a certain distance below the surface. 90% of infrared radiation is absorbed in the first meter of the water’s surface, and only 1% can reach past two meters in pure water 1. This is why the surface of most bodies of water are warmer than the depths."


 So I have a question, is the heating we see only from solar radiation heating the surface water and mixing or does some radiation  penetrate through ice and heat the water the ice is floating in ?


https://www.fondriest.com/environmental-measurements/parameters/weather/photosynthetically-active-radiation/
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: ghoti on July 07, 2019, 06:59:11 PM
You might be confusing different parts of the spectrum. Infrared is not included in PAR (400-700nm) so the absorption characteristics of IR don't necessarily translate to overall solar energy absorbed. Also most of the heating would likely be from the visible spectrum being absorbed and converted to heat.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 07, 2019, 08:11:53 PM
The article I linked does describe the different wavelengths and says that heat from infrared  90% is absorbed in the top meter of water . PAR is visible light but I don't see how much heat it carries or to what depth . I assume visible light carries much less heat and I was only using PAR as some sort of proxy for light intensity on any given day. I was thinking the heat we see is from infrared light at the surface mixing to depth .
 I spent most of my life as a commercial diver. The heat from the sun notably affects the top meter and when you are diving in cold water 45-55 F you can feel the warm surface water on sunny days when you ascend from depth and swim back to the boat.
 Anyone have some ideas about how much heat is  carried with visible light through water or whether
all the heat we see at 6 meters is via mixing of surface water and the heat supplied is infrared?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 07, 2019, 09:12:50 PM
I have no idea about absorption in water, but most of the energy in sunlight is in the visible spectrum, which is why both plants and our eyes are adapted to use it. Unless I am completely confusing things. So infrared absorption should not be the important factor.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 07, 2019, 10:11:46 PM
Oren, Watts from infrared at the surface are about 55% of total with visible light at 42% . 90% of heat from infrared is absorbed by top meter of water. So the visible light does probably heat water at depth. Less as the red end of the spectrum which carries the more energy and absorbs shallower than the blue end.
 If there is a lot of ice floating around in the top meter of water it would seem like the heat from infrared would contribute to melting ice but the heat from visible light might be what is heating water at 6 meters below the ice. It would at least help explain why the increases in PAR and increases in seawater temperatures are so closely correlated.
 Once the ice melts then the heat from infrared and visible light will heat surface waters down to the thermocline. My best guess.


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: gerontocrat on July 07, 2019, 10:36:33 PM
I have no idea about absorption in water, but most of the energy in sunlight is in the visible spectrum, which is why both plants and our eyes are adapted to use it. Unless I am completely confusing things. So infrared absorption should not be the important factor.
Oren, part of me wants to thank you and another part doesn't. Your post sent me to read up on this and my brain hurts.
So far I have gathered that:-
- just about all the heat absorption in the oceans is through visible light,
- nearly all the infrared radiation is absorbed in the first few micrometers of the ocean where the thermal skin layer (TSL) exists.
- so  IR radiation does not directly heat the upper few meters of the ocean.

BUT
- due to AGW there is an increase in incoming longwave radiation from clouds,
- this in turn causes additional energy from the absorption of increasing IR radiation into the TSL,
- more of the surface to air heat loss is from the TSL.
- Thus, more heat beneath the TSL is retained leading to the increase in upper ocean heat content.
See link below.
Just think - a few micrometers of surface ocean water heated by increasing infrared radiation the only reason oceans can keep their increased heat.


But heating of the ocean itself is nearly all from visible light and the shorter the wavelength the more effective it is. I read somewhere that while at the tropics in clear water enough energy for photosynthesis can reach as deep as 80 metres, in polar water its more like 10 metres.

Postings above are saying that +ve SST anomalies in the Chukchi/Bering are reaching depths to 100 metres. Something else is going on to get the heat to that depth.
_____________________________________________________________
https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2017JC013351
The Response of the Ocean Thermal Skin Layer to Variations in
Incident Infrared Radiation

Quote
Abstract Ocean warming trends are observed and coincide with the increase in concentrations of greenhouse gases in the atmosphere resulting from human activities. At the ocean surface, most of the incoming infrared (IR) radiation is absorbed within the top micrometers of the ocean’s surface where the thermal skin layer (TSL) exists. Thus, the incident IR radiation does not directly heat the upper few meters of the ocean. This paper investigates the physical mechanism between the absorption of IR radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that given the heat lost through the air-sea interface is controlled by the TSL, the TSL adjusts in response to variations in incident IR radiation to maintain the surface heat loss. This modulates the flow of heat from below and hence controls upper ocean heat content. This hypothesis is tested using the increase in incoming longwave radiation from clouds and analyzing vertical temperature profiles in the TSL retrieved from sea-surface emission spectra. The additional energy from the absorption of increasing IR radiation adjusts the curvature of the TSL such that the upward conduction of heat from the bulk of the ocean into the TSL is reduced. The additional energy absorbed within the TSL supports more of the surface heat loss. Thus, more heat beneath the TSL is retained leading to the observed increase in upper ocean heat content.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 07, 2019, 11:00:04 PM
Gerontocrat, We haven't had PAR sensors on the ITP buoys in the past. It is another tool in the toolbag.
Since PAR is mostly used to inform bio productivity using them to inform temperature transfer under the ice is probably little more than speculation on my part.
 The heat to 100 meters is < 50 meters surface fresh water and  from 50 to 100 meters Pacific Warm Water at the ITP 110 location. They have different origins and the heat in each has different sources.
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: gerontocrat on July 07, 2019, 11:38:19 PM
It is another tool in the toolbag.

The heat to 100 meters is < 50 meters surface fresh water and  from 50 to 100 meters Pacific Warm Water at the ITP 110 location. They have different origins and the heat in each has different sources.
My ignorance on this subject is almost total.
I posted about this Thermal Skin Layer simply because I was stunned - I had no idea about it at all.

One thing I have learnt is-
- the tool bag isn't big enough,
- there are not enough tools in it,
- the need to know something is inversely proportional to the funds provided to find out.

The (lack of/pitifully small) buoys programme is a classic demonstration of the above.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Pragma on July 07, 2019, 11:40:07 PM
Oren, part of me wants to thank you and another part doesn't. Your post sent me to read up on this and my brain hurts.

I would like to extend the same sentiments to you  :) but I am glad I read it. There is a lot in there that is not intuitive. Thank you for the link.

So, if I understand it correctly, the IR energy is re-radiated to the atmosphere, contributing little to the water temperature and bounces between the surface and the various GHGs, with, of course, a portion making it back to space?

Unfortunately, it does not cover the issue of ice, and the heat transfer mechanism. I'm in the process of trying to figure that out.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 08, 2019, 03:31:57 AM
Thanks for the responses. Seems my memory was at fault, indeed peak energy is at the visible spectrum, but total energy is greater in IR.

(https://onelephantsandbacteria.files.wordpress.com/2017/10/solar_spectrum.png?w=700)

(https://heatisland.lbl.gov/sites/default/files/Solar%20Energy%20Spectrum.jpg)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 08, 2019, 01:32:52 PM
A more detailed look at PAR vs temperature for itp110, day150-186.
Temperature rose before par but there is also drift and current to consider.
apologies for the day scale.

Recent atmospheric conditions, worldview, jul3-8. Lost track of it. Better call Binntho ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 09, 2019, 01:08:32 PM
106 hour loop, Chukchi sea, band M15 with colors inverted and increased contrast for detail.  It appears that some of the warmest waters are those that are pushing north, just east of Wrangel Island.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 09, 2019, 05:35:45 PM
Nice. You found what you were looking for, and reasonable agreement with mercator.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 10, 2019, 02:55:14 PM
A detailed look at the sami for itp107. Once again temperature not really corrrelating with PAR at 6m but 107 has just left the chukchi plateau. I was hoping the profiler might continue once in deeper water but the last 4 profiles are stuck at 206m.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 12, 2019, 01:04:12 PM
location, temperature, salinity and density for whoi itp110, day173-193 (click to run)
The profile still struggling, possibly with high drift speed. see https://www.whoi.edu/page.do?pid=163197
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 18, 2019, 10:25:32 PM
itp110 might be giving some open water readings soon (assuming it floats). All the floes in the approximate area are pretty small now.  https://www.whoi.edu/page.do?pid=163197
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 23, 2019, 10:52:41 PM
itp110 temp/salinity not as revealing as might be hoped recently, day173-204. High drift speed
click to run
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: slow wing on July 24, 2019, 04:37:04 AM
Inspired by your salinity movies, uniquorn, the illustration below is a suggestion for displaying the actual physical data they are based upon.

It would give a 'traffic light' of salinity at e.g. 0m, 30m, and 100m at the location of each recording device on that date - whether from a tethered buoy, drifting buoy or a ship.


My main immediate motivation in suggesting this is that it would allow a movie that extends back before the June 2017 start of the mercator display movie that uniquorn posted here on the 2019 melting season thread (https://forum.arctic-sea-ice.net/index.php/topic,2591.msg215319.html#msg215319). That would give us a longer term view of how the salinity has changed.

I realize that it would probably be a lot of work to make this, but I think to could be a useful visualization tool. The picture is just an illustrative cartoon - I'm hoping someone will be kind enough and interested enough to produce such a display, or similar, using the actual data. (It's beyond my own personal skills at the moment, unfortunately.)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 24, 2019, 05:09:28 PM
Phil just posted this paper on the increased heat content of the halocline in the Beaufort Gyre.

https://advances.sciencemag.org/content/4/8/eaat6773

Implications and outlook
" The doubling of BG halocline heat content over the past three decades appears attributable to a warming of the source waters that ventilate the layer, where this warming is due to sea ice losses in the Chukchi Sea that leave the surface ocean more exposed to incoming solar radiation in summer. The effects of an efficient local ice-albedo feedback are thus not confined to the surface ocean/sea ice heat budget but, in addition, lead to increased heat accumulation in the ocean interior that has consequences far beyond the summer season. Strong stratification and weak mechanical mixing in the BG halocline ensure that significant summertime heat remains in the halocline through the winter.

With continued sea ice losses in the Chukchi Sea, additional heat may continue to be archived in the warm halocline. This underscores the far-reaching implications of changes to the dynamical ice-ocean system in the Chukchi Sea region. However, there is a limit to this: Once the source waters for the halocline become warm enough that their buoyancy is affected, ventilation can be shut off. Efficient summertime subduction relies on the lateral surface front in the NCS region between warm, salty water that is denser to the south and cooler, fresher water that is less dense to the north. For longer-duration solar warming (that is, longer-duration ice-free conditions in the region), SSTs on the south side of the front may become warm enough (around 13°C, under the assumption of a 1.5-month ice-free period dominated by solar absorption) that the lateral density gradient is eliminated [see (24)]. It remains to be seen how continued sea ice losses will fundamentally change the water column structure and dynamics of the Arctic halocline. In the coming years, however, excess BG halocline heat will give rise to enhanced upward heat fluxes year-round, creating compound effects on the system by slowing winter sea ice growth."
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 24, 2019, 05:52:21 PM
I think this year we have had the 1.5 months of ice free conditions dominated with solar absorption in the Chukchi . We also have very warm water moving north through the Bering Straits and in the Alaskan Current. At Red Dog Dock it has been at or above 13C for weeks now.
 Are we close to the " lateral density gradient " being eliminated? 

" Once the source waters for the halocline become warm enough their buoyancy is affected, ventilation can be shut off. "    So if I am reading this correctly if the Pacific water moving north over the Chukchi
Warms sufficiently it won't sink ? If that is the case then all that heat will stay up in the surface where it can interact with the surface layer and the ice ?  Whoa baby

 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: aslan on July 24, 2019, 09:57:50 PM
Probably not yet, but we are nearing this point. The ITP110 buoy, on the 19th -the last complete profile....- was showing strong heat storage at depth, and a thickening of the halocline. Graph can be compared with Fig. 1 here : https://advances.sciencemag.org/content/4/8/eaat6773 and Fig. 2 and Fig. 5 here : https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2014JC010273

But there is also a freshening of the halocline, in connection with its thickening and shoaling (cf second paper). All in all, heat is still building up in the Beaufort but instability of the thing is also probably increasing, while the Chuckchi sea is effectively trying hard to reach breakdown but is not yet fully at this point.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 24, 2019, 10:18:28 PM
In this particular case, what are we looking for in a temperature vs salinity chart? I ask because it may be a more efficient way of diplaying the profiles.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: aslan on July 25, 2019, 03:21:33 PM
In this particular case, what are we looking for in a temperature vs salinity chart? I ask because it may be a more efficient way of diplaying the profiles.

Salinity is usually used as a marker for layers of water. Usually, S between 31 and 33 is thought to be the Pacific Warm Water https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2014JC010273 but a freshening of warm waters is ongoing and should increase instability of the water column, as S is around 28 near surface, with the risk that this warmth make surface by mixing. At greater depth, the max at around S=35 is Atlantic water. In Summer, water are fresher (sea ice melt, water runoff) and warmer, with a positive trend due to warming (water source from Chukchi sea is fresher and fresher, warmer and warmer). This is showing in the Beaufort Gyre, with a higher max in temperature at lower salinity for the Pacific Water Layer. There was even some ITP profiles with a Tmax with salinity near 30, and a Tmin with salinity near 28... of course freshening of Pacific Water must reach a limit, and in the same time, as said by Bruce Steele, the warming of Chukchi Sea will shut down the donwelling. I am not sure where we are going, but here we go. And the Ocean is definitively heavily disturbed, there is way too much heat which was accumulated this season, and it is not over.

(https://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/102845529/1_2.jpg)

Inspired by your salinity movies, uniquorn, the illustration below is a suggestion for displaying the actual physical data they are based upon.

It would give a 'traffic light' of salinity at e.g. 0m, 30m, and 100m at the location of each recording device on that date - whether from a tethered buoy, drifting buoy or a ship.


My main immediate motivation in suggesting this is that it would allow a movie that extends back before the June 2017 start of the mercator display movie that uniquorn posted here on the 2019 melting season thread (https://forum.arctic-sea-ice.net/index.php/topic,2591.msg215319.html#msg215319). That would give us a longer term view of how the salinity has changed.

I realize that it would probably be a lot of work to make this, but I think to could be a useful visualization tool. The picture is just an illustrative cartoon - I'm hoping someone will be kind enough and interested enough to produce such a display, or similar, using the actual data. (It's beyond my own personal skills at the moment, unfortunately.)

This said also, Mercator is not seeing the warming and freshening of Pacific Water... The profile is for the model where the ITP buoy made the 601th profile, on the 19th July of this year (cf. above). Quite a difference. And the same on the 19th still, over northern Chukchi sea. For making a movie, I think I don't have the time, nor the motivation, nor the bandwith :s
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 26, 2019, 10:59:16 AM
Thanks aslan.
The floe that whoi itp110 is/was tethered to must be very close to 0m thickness today. Profiler still struggling at 8-100m but the microcat and sami charts suggest open water. https://www.whoi.edu/page.do?pid=163197
Location is close to the centre of the first image. https://go.nasa.gov/2K8EKoM.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 27, 2019, 11:26:34 AM
whoi itp110 almost certainly in open water looking at today's lovely clear worldview image. itp103 rough location is also circled. Buoy temperature settling down to 2-3C. PAR on the sami still very high.
@Bruce Steele do you think the internal buoy temperature is a reasonable indication of SST now that most of the buoy is sitting in water.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 28, 2019, 09:57:10 AM
@Bruce I guess that's a no. It's reading over 8C this morning just off the ice front.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 29, 2019, 10:24:52 AM
whoi itp110 at beaufort ice edge with microcat and sami mounted at 6m depth. Both indicating temperatures above zero today. Internal buoy temperature at 7.6C.
Profiler only occasionally managing to move between 7m-90m
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Rich on July 29, 2019, 11:22:12 AM
 I'm not an expert on much, but I do check the SST:s from two different sources (windy and GFS) on a daily basis. You may have noted a few recent  posts on the main thread tracking SST data.

I've never noted anything close to the kind of 7-8C temperature inside the buoy in the ice edge SST. Pretty sure that what is going on inside the buoy is not reflecting SST.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 29, 2019, 05:05:09 PM
Uniquorn, Having melted out of the pack and with the increases in PAR at itp 110 I would expect temperatures at the microcat depths to continue their increases. And the internal bouy temperatures are not very informative.
 The salinity on the microcat page  at the itp 107 location is interesting to me. I thought most of the fresh water flowing out of Siberian rivers moved to the location off the Chukchi Hinderlands where itp 107 currently resides but I am wondering how the fresh water from Siberian rivers moves across the Chukchi plateau . I am wondering if there is more mixing with the surface layer than the water that flows out of the Bering Sea?
So does the Bering Sea outflow mix with the Siberian waters before they both sink or does some of the Siberian fresh water stay on the surface as it travels across the Plateau ?

Also could you show the PAR data for itp 107 ? The readings exceed the range of the chart on the main page. I should be able to find the answer in the metadata but I haven't been able to do so. Thanks in advance.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 29, 2019, 10:21:47 PM
download itp107grddata and extract. Its at the bottom itp107sami.dat.
out of the loop for a bit but will keep an eye on this thread if you need anything.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 01, 2019, 10:47:18 PM
Reposting these for reference.
noaa bathymetry with unihamburg amsr2-uhh overlay, september minimums 2012-2018
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 01, 2019, 10:51:19 PM
noaa bathymetry with unihamburg amsr2-uhh overlay, mar21-jul29
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 01, 2019, 10:52:34 PM
mercator salinity 34m with unihamburg amsr2-uhh overlay, mar21-jul30
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Shared Humanity on August 01, 2019, 11:37:35 PM
Great animations! I forgot how crappy the ice was at the end of the 2016 melt season.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 05, 2019, 07:11:59 PM
itp buoys updating again today. Here is whoi itp110 day 210-217  https://www.whoi.edu/page.do?pid=163197
click to run
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 07, 2019, 11:13:03 PM
gmrt bathymetry with unihamburg amsr2-uhh overlay at 75% transparent. Open water, normally dark blue, set to fully transparent, jul1-aug6.
Posting full arctic here for a while for those who are interested.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on August 07, 2019, 11:23:58 PM
Thank you uniquorn.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 07, 2019, 11:51:05 PM
Thank you uniquorn.
no pic, didn't happen ;)
sometimes I don't see things till they are online
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 13, 2019, 10:24:30 PM
update on whoi itp103 which seems to be struggling with drift speed and/or turbulence since day209 over the beaufort shelf west of Banks Island.
Only showing temperature as the profiler is hardly moving at the moment.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 13, 2019, 10:44:09 PM
update on whoi itp110. Latest profile is day118, a couple of days ago but look at the drift speed.
Only showing temperature here.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: MyACIsDying on August 14, 2019, 12:14:04 AM
I see you mentioned it earlier but the floe melting out could be causing the increase in drift speed right? Last position on 2019/8/13 64548 UTC : 72.2444° N, 138.7633° W
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 14, 2019, 12:15:37 AM
highly likely a contributing factor. There was also a small cyclone over that area a couple of days ago
https://earth.nullschool.net/#2019/08/11/2100Z/wind/surface/level/orthographic=-43.48,86.03,1542/loc=-138.270,71.130

Comparison of mercator 0m salinity, jul1-aug12, 2017-2019
maybe overlay the ice tomorrow
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 15, 2019, 12:31:18 AM
maybe overlay the ice tomorrow
or not
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: aslan on August 16, 2019, 04:54:21 PM
And now ITP 110 has hoisted the white flag and surrender. No news since two weeks. Too bad, as Mercator is showing extreme warmth in Beaufort. It should have been interesting to see what really happens here. The build up of heat shown at 30m and 100m is like nothing ever seen. Will this have an influence on refreeze season ? And Mercator was shown to be warming not enough compared to ITP 100. Depite this, in part of the Beaufort Sea, the big mess is going on and on, with a loosening of the stratification and a build up of energy wich is beyond superlatives and the "spot the difference" game ... Where now the Pacific layer and the halocline ? Where is the freshening and the cooling ? I don't know where we are going at this pace, but here we go.

P.S. : There is no special reason for a comparison with 2016, it was only to give a point of reference for a year wich was in its own quite bad for Arctic.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: aslan on August 17, 2019, 04:53:35 PM
I make a quick map to compare 2019 on the 26th of August (forecast from Mercator) to mean from 2016, 2017, 2018. I don't know why, I was not able to download data for prior years, I don't know why... Excepted for the Barents sea which is cooler than over the 3 previous years (also the case for SSTs with a true base period), everywhere the warmth is showing, and even in the central basin there is streams of abnormally warm temperature.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on August 17, 2019, 05:38:59 PM
Mercator has made multiple "improvements" of their model and their data sets over the years. Every time they make an improvement the older images are removed from public access. I find it frustrating when it becomes impossible to go back more than a year or 2 to make comparisons.

Some very important things are happening in the Beaufort and other Arctic seas, but we are almost blind to what's happening because of the paucity of buoys and ships monitoring the Arctic. It's crazy that there isn't better monitoring of the Arctic.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on August 17, 2019, 06:46:06 PM
110 took quite a battering, I'm guessing intersecting waves reflected off the shelves caused a huge pressure spike on the 15th July, it looks like it 'bounced' generating tauroidal 'smoke ring' type wave structures which spread across the whole basin sending shockwaves back which damaged 110 when it approached the shelf/amundsen generated tidal vortices around the 5th. 1.7mb gif won't be here long
link (https://media.giphy.com/media/WQrsrIrvzGSAgLmXmK/giphy.gif)
switched gif for link
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on August 17, 2019, 07:07:55 PM
Wow, that's fascinating. Thanks for sharing John!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: aslan on August 17, 2019, 08:34:25 PM
Yes it is probably the explanation, despite Copernicus showing data available since 2006. And yes it is really frustrating to be blind while the Beaufort sea is beaten like never. The beaufort gyre is quite an important thing, but who know what is really happening ?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 17, 2019, 08:59:47 PM
Well at least we have 2017-2019 to compare.
Mercator salinity 0m with unihamburg amsr2-uhh overlay at 50%, jul1-aug15

I remove my animation when it reaches 61 downloads. I don't know why.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: gandul on August 18, 2019, 03:15:20 PM
Question from newbey:
What’s first, the egg or the chicken?
That was not the question
We know that ice in the Atlantic edge forces Atlantic currents such as W. spitsbergen to sink.
However atlantification prevents ice to form at Barents and further North in Winter, allowing for extreme edges to the North (2016 to 2018)

So what happened this year that the ice was not contained, drifted South in winter, and forced current to sink earlier so that the ice edge is very robust between Svalbard and FJL ? In other words, who put the 2019 egg without the 2018 chicken? Or how did the chicken survive?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: NotaDenier on August 18, 2019, 03:35:13 PM
German ship to drift near pole
From next month, Rex will head a major winter expedition. The Polarstern (Polar Star), a German research ship, will drift across the Central Arctic by tying itself to a large ice flow for months through the winter dark.
"We'll be north of the 80th parallel the entire time, and for much of it, we'll even be in the direct vicinity of the North Pole," Rex said.
Aside from Norway's 19th century explorer Fridtjof Nansen, few had conducted an ice-drift winter analysis so far north in the "epicenter of global warming," he added.
Norwegian researchers warned the Arctic Council in May that the North's chilled stratified waters — vital for unique fish life — were already "shifting" to resemble mixed Atlantic waters because of temperature rises.

https://www.awi.de/en/focus/mosaic-expedition/interview-with-markus-rex.html

Wow should be some good data from this expedition.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on August 18, 2019, 04:04:08 PM
I sure hope so, NotaDenier. Looking forward to it.

Until then we only have the buoys.

Here is 110 drifting towards the coast, getting warm and fresh.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 18, 2019, 06:21:37 PM
Here is 110 drifting towards the coast, getting warm and fresh.
drift track is up to date. Unfortunately, as noted upthread, the last profile (and microcat data) was aug6. https://www.whoi.edu/page.do?pid=163197

Last buoy status on 2019/8/18 64601 UTC : temperature = 1 °C, battery = 10.78 V
Last position on 2019/8/18 64601 UTC : 70.6566° N, 139.3028° W
Last profile (number 640) on 2019/8/6 602 UTC
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on August 19, 2019, 05:28:30 PM
Thanks for the correction, Uniquorn. Should have read that more carefully.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 20, 2019, 01:52:22 PM
another view of caa/cab crack, worldview may1-aug19. Posting here for reference (~7MB)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2019, 03:12:36 PM
Following up on persistent ESS ice in post https://forum.arctic-sea-ice.net/index.php/topic,2591.msg224137.html#msg224137.
Please see https://forum.arctic-sea-ice.net/index.php/topic,2890.msg224371.html#msg224371 for further details
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2019, 03:50:43 PM
moved to https://forum.arctic-sea-ice.net/index.php/topic,2890.msg224371.html#msg224371
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2019, 11:22:58 PM
Looking for arctic bathymetry data I came across iview4d, freely available here after registration https://www.deepreef.org/technology/44-fledermaus.html  (~170MB)
Quote
iView4D is a free viewer for files in the Fledermaus *.sd or *.scene file formats. Fledermaus scenes are larger files that contain a number of individual sd objects. The iView4D program contains only the basic viewing capabilities of Fledermaus
The Fledermaus visualisation software gives ocean mapping scientists a detailed view of the seafloor shape and depths. By using artificial sun-shading and colouring the depths using various colour maps, it is possible to highlight the subtle relief of the seabed and to quickly understand the variation in depths.
NOAA's sd file for the arctic is available here https://www.ngdc.noaa.gov/mgg/bathymetry/arctic/grids/version3_0/  (374MB)

Quick example below:
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 26, 2019, 12:22:00 AM
whoi itp89 near the Mclure Strait moved at speed round the corner eastwards (off the map)  https://www.whoi.edu/page.do?pid=148096

Data from ITP89 deployed in September 2015
Last buoy status on 2019/8/25 28 UTC : temperature = 2.25 °C, battery = 10.884 V
Last position on 2019/8/25 14 UTC : 73.3117° N, 107.1301° W
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: petm on August 26, 2019, 12:59:03 AM
Whoa, suddenly off the chart.

Also, iview4d -- very cool!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 28, 2019, 12:41:52 AM
New whoi buoy itp116 north of Greenland. https://www.whoi.edu/page.do?pid=164836
No microcats, only the profiler.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 29, 2019, 08:17:52 PM
Quote
Woods Hole Oceanographic Institution
Published on 26 Aug 2019
Since 2003, the Beaufort Gyre Exploration Project at the Woods Hole Oceanographic Institution has given us an up-close look at one of the fastest-changing parts of the world. In 2018, the Ocean Media Institute at Montana State University sent Hugo Sindelar to join the annual expedition aboard the Canadian icebreaker Louis S. St. Laurent to see how the scientists and engineers involved in the project bring back their hard-earned data and to hear what they’ve learned so far.

https://www.youtube.com/watch?v=QMmQ0mMycXE

Ocean Media Institute: http://oceanmediainstitute.org
WHOI’s Beaufort Gyre Project: https://www.whoi.edu/beaufortgyre
Fisheries and Oceans Canada: http://www.dfo-mpo.gc.ca/index-eng.htm
Canadian Coast Guard: http://www.ccg-gcc.gc.ca/eng/CCG/Home
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 03, 2019, 11:05:24 PM
Posting here for reference. Clear weather over nearly all of caa and greenland, sep3.
Worldview, aqua modis, light adaptive contrast.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 03, 2019, 11:54:26 PM
whoi-itp103 heading into amundsen gulf. Profiler is stuck so posting microcat1 6m depth
itp107 has nearly completed the ocean gyre. Profiler is also stuck. cat1 indicating another significant temperature increase recently.
itp116 profiler is working but no cat fitted.
itp89, still off the map but coords indicate it is deep into goldsmith channel.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 05, 2019, 09:42:27 PM
noaa sst anomaly 20180904-20190904
ffmpeg -crf31, some loss of quality to reduce file size
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 05, 2019, 10:22:02 PM
It looks like itp103 is dragging along the ocean floor since day 209. Here showing temperature and salinity from the profiler, day 203-248 (today) Depth matches quite well as it crosses deeper water past banks island.
Fresher water at the entrance to Amundsen Gulf at 6m from microcat1, a little warmer too, though not the spike as it passed Mclure Strait.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 06, 2019, 10:22:36 AM
Rough location of itp103 at the entrance to the amundsen gulf, worldview, sep3-6
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 07, 2019, 01:01:06 PM
A very different profile for whoi itp116 on the atlantic side, day234-250(sep7)
https://www.whoi.edu/page.do?pid=164836
The salinity scale is the same as upthread for comparison. Temperature had to be increased to 1.5C
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 07, 2019, 10:14:21 PM
amsr2-uhh overlaid at 60% transparency onto mercator SST, mar21-sep6
removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 09, 2019, 12:41:38 PM
Temperature and salinity rise recently on the microcats at 6m and 7m 5m and 6m on itp103 at the amundsen gulf entrance. Maybe the floe above has nearly melted or is it warmer water from below?
https://www.whoi.edu/page.do?pid=163356
polarview, sep8
edit: Difficult to tell from the profiler dragging along the ocean floor, temperature, day 244-248. Temperature appears to be rising during periods when the depths are constant.

I wonder if a secondary depth sensor on a short line attached to the bottom of the profiler could stop it before it reached the ocean floor in shallower locations.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: sailor on September 10, 2019, 09:13:00 PM
Temperature and salinity rise recently on the microcats at 6m and 7m 5m and 6m on itp103 at the amundsen gulf entrance. Maybe the floe above has nearly melted or is it warmer water from below?
https://www.whoi.edu/page.do?pid=163356
polarview, sep8
edit: Difficult to tell from the profiler dragging along the ocean floor, temperature, day 244-248. Temperature appears to be rising during periods when the depths are constant.

I wonder if a secondary depth sensor on a short line attached to the bottom of the profiler could stop it before it reached the ocean floor in shallower locations.
If you see the eddies that the ice forms around itp location and many other locations, that indicates mixing with surrounding water and one would expect temperature spikes
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 12, 2019, 11:19:43 PM
itp103 temperature, salinity and pressure now looking quite volatile at 5-6m. Well at least battery voltage is steady :) Too cloudy for worldview today.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 16, 2019, 10:02:07 PM
Mixing. whoi itp103, sep16.
6m temperature over 2C
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 17, 2019, 12:25:14 AM
A salinity hiccup on whoi itp105 over the last 3 days on both microcats at 5m and 6m
https://www.whoi.edu/page.do?pid=163456
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 17, 2019, 12:38:43 PM
Following up on the 2 buoys above, here is amsr2-uhh overlaid onto mercator 0m temperature at 60% transparency, amundsen gulf and mclure strait, jul1-sep15. amsr2-uhh 0% concentration, normally dark blue, has been set to fully transparent.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 18, 2019, 07:56:54 PM
ascat showed some weather over itp105, and an overlay of Aleph_Null's nullschool hindcast would appear to confirm it is associated with fast moving high pressure cyclone, but the dates don't really match up with the low salinity so...
don't know

ascat, north of CAA, day240-260
ascat overlaid with h~f_190906-190911_iwpd_850hPa
edit: technote - poor scaling on the overlay
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 20, 2019, 02:56:40 PM
whoi itp116 is the only itp completing full profiles. The rest have flat motor batteries I think.
With the stupid questions thread in mind, here is a closer look at temperature(purple), salinity(red) and density(green), 10-50m, day234-263.
There isn't much thermocline to see at 34m close to the pole(~0.03C), the halocline is more pronounced.
Maybe the mosaic buoys will provide some more revealing data
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on September 20, 2019, 05:59:00 PM
New profiler ITP119! \o/
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 20, 2019, 11:55:48 PM
Great news :)
Reposting  whoi itp110 7m-50m from 2018, day264 to 2019, day120 (at location -134.8350  73.6623N) with location insert.

edit: corrected label and added part2
whoi itp110 7m-80m from 2019, day123-218
density green, temperature purple, salinity red
temp    -1.8 to 0.6C
salinity  27.5 to 31.2
density 1021.5 to 1025kg/m^3
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: MyACIsDying on September 21, 2019, 07:53:31 PM
It's hard to match the ITP buoys temperature & salinity profiles with their location using the standard plots provided, so I practiced my R and took a stab at it.

Because of the constraint of one type of value displayed per location point, I started with the average temperature of the 0-60 dbar ocean layer. I'd like to animate it based on date with a fading trail, but if anyone has suggestions for a better calculated value to display, let me know please.

L3 data was available for years 2005-2014
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: slow wing on September 22, 2019, 10:40:24 AM
It's hard to match the ITP buoys temperature & salinity profiles with their location using the standard plots provided, so I practiced my R and took a stab at it.

Excellent! Much appreciated initiative, MyACIsDying. This is a plot I've wanted to see often.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 22, 2019, 12:09:11 PM
if anyone has suggestions for a better calculated value to display, let me know please.
Very nice. As the data is quite old it may be more interesting to animate depthwise, rather than date. Perhaps a 10m average down to, say, 350m? If you are prepared to share code it would be most welcome on a dev thread.
This approach may also work well with the mosaic buoys.
L3 data time series would be handy for comparison with more recent data in similar locations though. Can you provide a link pls?
edit: I read the small print and see data goes up to 2019
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on September 22, 2019, 04:33:34 PM
SSS, 01. Sept 2018 to 20. Sept 2019, 10-day increments

Click to play
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on September 22, 2019, 04:54:20 PM
Salinity 30m, 01. Sept 2018 to 20. Sept 2019, 10-day increments

Click to play
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Pmt111500 on September 22, 2019, 09:51:25 PM
Yeah, Kara Sea starts to be pretty Atlantic.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 22, 2019, 10:34:03 PM
If the model is correct there is also a more clearly defined atlantic finger reaching into the Beaufort from the CAA. See https://forum.arctic-sea-ice.net/index.php/topic,2417.msg188825.html#msg188825 for animation going back to 2017.

This is interesting from the mosaic expedition:
 https://epic.awi.de/id/eprint/50082/1/Expeditionsprogramm_PS122.pdf   page 55
Quote
Outline The sea ice in the Arctic Ocean is changing under global warming, and there is evidence that the inflow of Atlantic water (AW) has reduced the upper ocean stratification enough, such that convective wintertime deepening of the mixed layer may have caused a sizable upward heat flux in parts of the Eurasian Basin. In the more permanently ice-covered central regions of the Arctic Ocean, it is thought that the halocline still prevents vertical mixing and thus, strong upward heat fluxes year-round. However, wintertime measurements hardly exist. Near-surface trapping of heat during the late summer has been of growing importance as the influence of solar radiation entering the ocean increases with snow melt, melt-pond formation and increasing open water fraction of the ice-pack. Observing a full seasonal cycle as well as studying the ice-ocean-atmosphere system in the Arctic at shorter timescales using an extended set of parameters will be extended in an unprecedented manner by MOSAiC. The specific focus of the OCEAN team is here on the physical parameters of the upper ocean, bounding on the sea-ice and the atmosphere, and the interaction with the lower parts of the water column. This will not only improve our understanding of the physics of the upper ocean at times where no or few measurements exist and throughout a full seasonal cycle but also improve our understanding of feedbacks with the sea-ice/snow, the lower atmosphere, biogeochemical processes and the ecosystem. The overall aim of our work is to understand, throughout all seasons, the dynamics in the upper Arctic ocean mixed-layer and the halocline on the scale of turbulent vertical mixing to the (sub)mesoscale, embedded in the Arctic system of large-scale advective pathways of different water masses.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: MyACIsDying on September 22, 2019, 11:53:23 PM
if anyone has suggestions for a better calculated value to display, let me know please.
Very nice. As the data is quite old it may be more interesting to animate depthwise, rather than date. Perhaps a 10m average down to, say, 350m? If you are prepared to share code it would be most welcome on a dev thread.
This approach may also work well with the mosaic buoys.
L3 data time series would be handy for comparison with more recent data in similar locations though. Can you provide a link pls?
edit: I read the small print and see data goes up to 2019

Thanks, your suggestion turned out nice and I want to go deeper but ran out of time, so 0-350m it is for now. I'll post the R code over at the dev thread with some warning of amateur practices. Only for the final.zip data again, the others have different structures but next on the list.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 23, 2019, 12:16:34 AM
Very, very nice, an arctic ocean visualisation with the same scale from top to bottom (well 350m)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on September 23, 2019, 07:55:25 AM
Very nice indeed! Thank you, MyACIsDying!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 23, 2019, 01:16:22 PM
Does R do anything 3D? Playing around with imageJ gave me this so far...
going to dev thread
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on September 23, 2019, 01:27:50 PM
Let it rotate so you hit every dot. Looks awesome!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 27, 2019, 09:26:48 PM
I'll post the R code over at the dev thread with some warning of amateur practices. Only for the final.zip data again, the others have different structures but next on the list.
Having fun installing R and the dependencies dependencies, nearly ready to test. Also played around with various overlays but the projection used here is different. 3D is too much for me at the moment.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 28, 2019, 10:33:08 AM
3 new whoi itp buoys for the CAB/Beaufort now, itp117, 118 and 119.
itp116 drifting close to the pole.
itp117 and 118 have SAMI with temperature but no salinity   :-\
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 28, 2019, 12:50:22 PM
And now ITP 110 has hoisted the white flag and surrender.<snippage>
Were those temp/salinity charts from itp110 or mercator?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 01, 2019, 11:56:00 PM
Ice mass balance buoy, Beaufort.
https://www.cryosphereinnovation.com/386840
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: MyACIsDying on October 03, 2019, 12:11:03 AM
Does R do anything 3D? Playing around with imageJ gave me this so far...
going to dev thread
R does a lot for me when I talk right to her :) I'm testing with translating lon/lat into xy coords so I can use base ggplot2 functions like geom_path with coordinates offsets, only y axis down per layer for now to produce the first image. need to optimize it further so I can program angles to rotate the 'camera' around and see all sides. Would take to much processing for now. I'm starting to publish stuff on GitHub (https://github.com/macidR/arcticPlotting) if you're interested.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 06, 2019, 04:36:19 PM
Very interested. That's very close to what I've been thinking of. Thanks.
edit - itp116 has a smaller footprint for testing rotation.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 09, 2019, 03:38:44 PM
Large format mp4, amsr2-uhh over gmrt bathy, sep1-oct8. Pls download as I'll remove it within 48hrs (it's a bit large) -removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 16, 2019, 12:00:31 PM
mercator 0m temperature overlaid with uni-hamburg amsr2-uhh concentration. 0% concentration, normally dark blue, has been set to fully transparent. sep16-oct15. click to run.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 18, 2019, 01:01:03 AM
mercator 0m salinity overlaid with uni-hamburg amsr2-uhh concentration at 60% transparent. 0% concentration, normally dark blue, has been set to fully transparent. sep17-oct16. click to run.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 18, 2019, 10:57:00 PM
whoi-itp103 unsure where to go again at the mouth of the amundsen gulf. Another temperature spike at 6 and 7m, salinity also higher this time with less melt above.
https://www.whoi.edu/page.do?pid=163356
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 22, 2019, 08:14:08 PM
This may be a bit large for the mosaic thread so posting temporarily here.
56 mosaic buoy locations from the iabp arcti bupy table http://iabp.apl.washington.edu/maps_daily_table.html. Some of them either very close or duplicated. day292-295.
Labelling doesn't really work at a smaller scale.
Looks like a couple of helicopter trips during that period.

replaced with smaller version, day 283-296, no labels
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on October 28, 2019, 03:56:32 PM
What's up with this? The salinity alongside Greenland north and CAA is increasing according to Mercator. It could be due to refreezing, right? Or is this Atlantification?

GIF is showing 01.10.2019 to today, daily increments.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on October 29, 2019, 11:10:13 AM
Atlantification.
Looking poleward it seems there's tidal induced flows penetrating into Nansen/Amundsen basins via St. Anna trough, forcing surface melting south of the pole around the 90E M. and I'm guessing the eastward flow and bathymetry generates the more saline surfacing water around 140-135E 85N, and the semicircle of saline water it unites with. I suspect there's a certain amount of internal wave formation going on in the basins as a consequence and that when the harmonics are just right there's a reverse gradient formed north of Greenland that facilitates the wind driven departure of it's resident ice. When that wave complex moves back into the deep it'll draw more Atlantic water in.
(https://media.giphy.com/media/WqFdRcNMCBby9Ifu5k/giphy.gif) 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on October 29, 2019, 12:06:16 PM
Yes, John. Makes sense to me. Thank you.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 29, 2019, 11:56:11 PM
@bl some of that looking like upwelling but I haven't been watching closely.
@both. Best to make it clear what is being shown. In both cases it's SSS (0m salinity). Mercator not agreeing with hycom on the low salinity around 90E M. @johnm33 assuming you suggest bottom melt as air temps are ~-20C according to gfs and ecmwf. Unfortunately itp116 not near enough to confirm. https://www.whoi.edu/page.do?pid=164836

whoi itp103 temperatures peaking again at 5-6m. It looks more like a current than mixing. https://www.whoi.edu/page.do?pid=163356
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 30, 2019, 12:20:50 PM
Mercator temperature 0m, sep21-oct29 with uni-hamburg amsr2-uhh overlay at 60% transparent. (0% concentration fully transparent)
Mercator would appear to be struggling to model the rapid refreeze. click to run
The Mackenzie bay area is interesting. amsr2 indicating rapid refreeze and melt. Worldview image of oct27. Unfortunately it has been cloudy since then
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on October 30, 2019, 05:05:28 PM
@bl some of that looking like upwelling but I haven't been watching closely.

I agree. You don't think upwelling is contradicting atlantification though, right?

Will do a Mercator 30m GIF. I think this might help.

PS: 103 might be influenced by Pacific waters?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on October 30, 2019, 06:33:13 PM
Will do a Mercator 30m GIF. I think this might help.

Is it though?  :(

PS: Atlantic surely kissing the Beaufort Gyre.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 31, 2019, 12:04:03 AM
re itp103, Mercator 34m temperature tells a different story though it's not visibly clear at any depth on the model that pacific waters reach the amundsen gulf.
Bathymetry isn't particularly conducive to kissing along the chukchi plateau :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 31, 2019, 12:26:20 AM
More on kissing, whoi itp112 is just the other side of the chukchi plateau.
whoi have a nice selection of buoys out now and Bruce Steele's 50m thick warm layer in the Beaufort is not going away. https://www.whoi.edu/page.do?pid=165216
They also have 2 itp's in the mosaic area.

Quote
You don't think upwelling is contradicting atlantification though
With the proviso that my comments are mostly guesswork based on models, scant satellite data and the occasional buoy, no ;)
tech note: date labels are worth the effort
On the Beaufort I think it is worth rereading this post from aslan https://forum.arctic-sea-ice.net/index.php/topic,2417.msg215992.html#msg215992
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 31, 2019, 01:08:32 AM
weather cleared up over mackenzie bay, amsr2 doing a good job. The wind must have changed.
https://go.nasa.gov/2WszCl5
Also, Bering sea beginning to cool down at 34m after a warm summer :)
(scale as above)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on October 31, 2019, 03:49:46 AM
Uniquorn, I went back and reread the old thread with the post from Aslan . In the discussion section of a paper we were discussing
https://advances.sciencemag.org/content/4/8/eaat6773


“With continued sea ice losses in the Chukchi Sea, additional heat may continue to be archived in the warm halocline. This underscores the far-reaching implications of changes to the dynamical ice-ocean system in the Chukchi Sea region. However, there is a limit to this: Once the source waters for the halocline become warm enough that their buoyancy is affected, ventilation can be shut off. Efficient summertime subduction relies on the lateral surface front in the NCS region between warm, salty water that is denser to the south and cooler, fresher water that is less dense to the north. For longer-duration solar warming (that is, longer-duration ice-free conditions in the region), SSTs on the south side of the front may become warm enough (around 13°C, under the assumption of a 1.5-month ice-free period dominated by solar absorption) that the lateral density gradient is eliminated [see (24)]. It remains to be seen how continued sea ice losses will fundamentally change the water column structure and dynamics of the Arctic halocline. In the coming years, however, excess BG halocline heat will give rise to enhanced upward heat fluxes year-round, creating compound effects on the system by slowing winter sea ice growth.”

I am happy to see so many ITP buoys with temp.salinity contours sending data.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 01, 2019, 06:14:05 PM
whoi itp102-119 location and profile contours. Big difference between laptev and beaufort.
itp116 clinging to the lomonosov ridge.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Niall Dollard on November 03, 2019, 01:23:14 PM

PS: Atlantic surely kissing the Beaufort Gyre.

It's counterintuitive to look at the salinity chart and then see the sea areas that have started to freeze over already.

It's not so much the speed at which freezing has taken over the saltier Laptev, Kara and ESS but rather more why the less saline Beaufort has made such little freezing advancement. 

Of course there has been the incredible heat absorbed over the summer period but the surface has cooled sufficiently on much of the Russian side already. 

Synoptic weather patterns north of Alaska have not helped. This October Alaska has seen huge +ve mean temperature anomalies and these have advected north into the Beaufort. And the ocean currents are still feeding warmth up from the Bering Strait Chukchi and spreading east across the top of Alaska.

Persistent northerlies over the Beaufort are what's needed to encourage both ice freezing and southward advancement. 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 17, 2019, 06:38:22 PM
I wish I knew Niall.
Whoi itp buoys (https://www.whoi.edu/page.do?pid=165198) in the Beaufort for reference. Maybe those thick warm layers at 25m are starting to make a difference.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 20, 2019, 11:52:35 PM
PS: Atlantic surely kissing the Beaufort Gyre.
Looks like you finally got your kiss :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 25, 2019, 11:22:47 PM
whoi itp103 (both microcats stopped recently) popped back out of the amundsen gulf and 116 now heading for the fram
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 27, 2019, 10:23:15 PM
uni-hamburg amsr2-uhh overlaid onto mercator temperature 0m at 80% transparent. amsr2 0% concentration, normally dark blue, has been set to fully transparent. Chukchi, sep21-Nov26, Large.
Posting temporarily - removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on November 27, 2019, 11:31:33 PM
Well thats a keeper, so much to see, i can't express how much i appreciate your work here thank you.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on November 28, 2019, 05:32:56 PM
+1
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on November 30, 2019, 06:37:51 PM
uni-hamburg amsr2-uhh overlaid onto mercator temperature 34m at 60% transparent. amsr2 0% concentration, normally dark blue, has been set to fully transparent. sep21-Nov29, Large.
Posting temporarily
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 10, 2019, 08:01:33 PM
uni-hamburg amsr2-uhh overlaid onto mercator salinity 34m at 60% transparent. amsr2 0% concentration, normally dark blue, has been set to fully transparent. sep21-Dec9, Large.
Posting temporarily - removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 10, 2019, 09:14:32 PM
same as above over gmrt bathymetry. Transparency percentages optimised for looking at the pacific side. Nansen basin gets a bit lost under all that salinity.
Experimental, posting temporarily - removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 16, 2019, 08:10:47 PM
whoi adjusted the map to cover the westward drift for itp116. Interesting that the warmer water at >200m doesn't appear to get past the Lomonosov Ridge.
Datawise, I'd prefer a drift around the N Greenland coast to the the almost inevitable destruction of the profiler down the Nares. We'll see...
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on December 30, 2019, 10:11:38 PM
whoi itp's in the beaufort.....
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 02, 2020, 11:48:41 AM
comparison of 2014-2019, sep19-jan1 using uni-hamburg amsr2-uhh. removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Niall Dollard on January 02, 2020, 12:12:59 PM
Thanks Uniquorn.

1st Jan comparisons show the big variability on the Pacific front, but there probably has been less comment, in general on social media, on the variability of the Atlantic front.

Svalbard clearly stands out as an ice free island on 01/01/16 and 01/01/17. Then a slow build up after that to present day when it is similar to 01/01/15.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 06, 2020, 11:06:01 PM
Chukchi plateau drift, unfortunately itp112 profiler isn't moving on the cable. https://www.whoi.edu/page.do?pid=165216
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 06, 2020, 11:19:15 PM
whoi itp buoys in the Beaufort, location and profile.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 07, 2020, 06:12:47 PM
ascat overlaid with unihamburg amsr2-uhh at 80% transparent.
amsr2 100% concentration, normally white, has been set to fully transparent to allow ascat features to show through. Missing or poor quality ascat days have been duplicated with the nearest day causing stutter.
sep21-jan6 - posting temporarily - removed
ffmpeg -crf31 to reduce filesize
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 07, 2020, 09:01:57 PM
compressive strength zero to max
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength_nowcast_anim30d.gif

the rebound hadn't occurred to me before
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 17, 2020, 02:53:10 PM
https://go.nasa.gov/3am5TAP Atlantic side, jan7-17, rotated, north down.
Large, so posting temporarily. Replaced with a smaller gif
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on January 17, 2020, 05:30:21 PM
Link (https://gph.is/g/4DnybQn) Taken together the cloud streets and the break aligned with the islands suggest internal waves propagated in the basins are forcing orthogonal waves south and these are disturbing the ice as they wash up the contours.
Rebound, again suggests huge amount of activity at depth, at least some of which must be A.W forced into the basin by tides judging by Hycoms salinity gif.
(https://media.giphy.com/media/Ph75DaquSYZNwYUSNg/giphy.gif)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 18, 2020, 06:37:47 PM
An introduction to internal waves (http://www.vliz.be/imisdocs/publications/60/307760.pdf) is quite easy reading for a few pages.
Quote
Internal waves were discovered more than a century ago. One of the first observations is due to Helland-Hansen & Nansen [41]. They found that temperature profiles may change substantially within the course of just hours (Figure1.3); they ascribed this to the presence of "puzzling waves", an example of which is shown in Figure 1.4. They stressed the importance of this newly discovered phenomenon:
"The knowledge of the exact nature and causes of these "waves" and their movements would, in our opinion, be of signal importance to Oceanography, and as far as we can see, it is one of its greatest problems that most urgently calls for a solution" [p. 88]
1The horizontal currents associated with these waves extend to the surface;

Ice melt over the Yermak Plateau, north of Svalbard, shown in more detail below, is more likely related to the warm west spitzbergen current. This continues to FJL but at depth, so would require a mechanism to mix with colder surface water. ctr
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on January 18, 2020, 10:24:27 PM
"so would require a mechanism to mix with colder surface water" yes what I'm suggesting is that internal waves possibly generated by A.W. entering the basin as tidal surges, are travelling to Laptev and back towards Greenland are in turn generating orthogonal waves which are dashed against the bathymetry at depth, both north of Svalbard and at inconsistences in the gradients of the troughs and where the troughs terminate beneath Barentz. It's clearer in your 'season' (https://forum.arctic-sea-ice.net/index.php/topic,2888.msg244770.html#msg244770) thread animation though without the cloud streets suggesting extreme 'spin' I'd probably think simple wind action the likeliest explanation.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 18, 2020, 11:10:39 PM
<what I'm suggesting>  agreed. Internal waves acting on the nansen slope could be a mixing method. Maybe a couple of mosaic buoys will drift that way and give us some data.
T68 is the nearest thermistor buoy.
I think SST's (or near surface) north of Svalbard are warmer and may not need much mixing from depth. Reposting this argo float ani from here (https://forum.arctic-sea-ice.net/index.php/topic,2417.msg184302.html#msg184302) last year where there are also charts. Obviously it was earlier in the season. Will have a look at mercator tomorrow.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on January 19, 2020, 05:03:23 AM
internal waves possibly generated by A.W. entering the basin as tidal surges,

Illogical nonsense. The waves are generated by AW (atlantic waters?) how? Or in other words, what  mechanism do the atlantic waters use to generate these waves?

As for tidal surges, have you or anybody else for that matter ever seen a tidal surge in an open ocean? No, they do not exist. A tidal surge is a coastal phenomenon only.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 19, 2020, 10:14:15 AM
Tidal movement in the Barents, jul2019. From the rammb thread (https://forum.arctic-sea-ice.net/index.php/topic,2649.msg210915.html#msg210915)
Checking nullschool (https://earth.nullschool.net/#2019/07/04/1200Z/wind/surface/level/orthographic=-56.90,90.38,2811/loc=47.020,78.851) shows fairly steady easterly winds at the time.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on January 19, 2020, 10:41:43 AM
Uniquorn, forget about it. I had this discussion with Binntho before. He is very convinced that waves can't cause lateral movement - at all.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: morganism on January 19, 2020, 11:15:54 AM
 Ice disc forms in river, not Arctic , but still...

Didn't see this last year.

https://www.theguardian.com/us-news/2020/jan/19/maines-giant-spinning-ice-disc-looks-like-its-reforming

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 20, 2020, 11:51:28 PM
whoi itp116 profiler data stopped on jan12 :(
https://www.whoi.edu/page.do?pid=164836
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on January 21, 2020, 08:35:33 AM
:(

Edit: States "Last buoy status on 2020/1/21 10402 UTC" now.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 21, 2020, 10:38:34 PM
update of mercator 34m salinity, sep2017-jan2020
edit: forgot scale
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Freegrass on January 22, 2020, 04:34:06 AM
update of mercator 34m salinity, sep2017-jan2020
That's an awesome animation Unicorn. Thanks for that! It clearly shows that the bering strait gets its water from the saltier Russian side. Is there an animation like this for surface salinity?

I posted this on the freezing thread, but it probably belongs here. I guess you guys already knew about this tool?

Bering Sea: Salinity Climatological Fields
https://www.nodc.noaa.gov/cgi-bin/OC5/PACIFIC2009/showclimatmap.pl?MapType=bs
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 22, 2020, 12:00:34 PM
PSY4 animations available here (http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20191101/20200122/2/1). Be aware that the scale is not static.
Individual static scale maps are here (http://static-bulletin.mercator-ocean.fr/img/-1/psy4qv3r1/20200121/arc/A/psy4qv3r1_20200121_arc_salinity_0m.png) (just edit both dates in the address)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on January 25, 2020, 11:48:22 PM
Worth the read. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JC010310
"We conclude that tidal shear stresses at the bottom and the ice‐ocean interface facilitate the transport of warmer and saltier AW to the surface layers, while the effects of tides along the Siberian shelf result in mixing of fresh river runoff waters with saltier water below the eroding halocline. Mixed layers, being much thicker due to the effects of the critical latitude on the clockwise component of tidal currents, entrain saltier waters to the surface boundary layers. Along the Siberian coast with strong river runoff, thicker boundary layers result in mixing in halocline and penetration of freshened waters to depth. Finally we find that, in this particular model, tides are responsible for ∼15% of the ice volume reduction and the presence of more salt waters at the surface in average by ∼1–1.7 PSU (Figure 14). Tides significantly modify the freshwater pathways along the Siberian shelf, resulting in saltier water along the Greenland coast. Tides affect the fresh water and heat content in the AO, with a reduction in the former by 7% in the upper 100 m"
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 26, 2020, 10:54:37 AM
Also interesting from the mosaic thread: https://www.nature.com/articles/s41598-017-15486-3
Quote
To summarize, we have used co-located acoustic and CTD data to unequivocally demonstrate that there is a one-to-one correspondence of thermohaline stairsteps and acoustic layering. We were able to track a staircase continuously (with some interruptions due to ice breaking in between drift stations) for 36 h over a ship track of 91 km (Fig. 4a), and identify an isolated staircase, extending about 100 km laterally, in the Nansen Basin (Fig. 5). We also present observations of layers forming/disappearing and splitting/merging within a thermohaline staircase (Fig. 5d–f). Finally, we present, for the first time, continuous high frequency vertical displacements of individual steps within an Arctic thermohaline staircase caused by internal waves. It is hypothesized that a sudden transition within an internal wave, where much of the high frequency energy at the trailing side of the wave suddenly disappears, is related to shear instabilities.

The data presented here suggest that in order to fully understand vertical heat fluxes, not only the presence of staircases must be considered, but also the mixing caused by decaying internal waves, which is likely not accounted for in laboratory measurements, numerical simulations, or very localized (i.e., discrete profile) measurements. A synoptic view is needed where, ideally, acoustic observations similar to the ones presented here are augmented by concurrent CTD and microstructure observations. This acoustic observational technique should offer new insights into the mechanisms controlling layer formation and evolution, and eventually allow for greater understanding of interactions between double-diffusive convection and shear-induced turbulence, as well as their control on diapycnal fluxes.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 26, 2020, 11:01:06 AM
https://go.nasa.gov/2TX24MY, jan7-26, rotated, north down, FJL(left) and Svalbard(right)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 26, 2020, 03:53:52 PM
Looking closer at the breakaway ice edge north of FJL/Svalbard. FJL coast very top left.
rammb, very heavy contrast, jan22-26     https://col.st/ib7ix
GFS indicating wind fairly constant northeasterly at -28C or lower so it has to be warm water rising from depth doing that. Movement suggests tidal.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 27, 2020, 10:46:35 AM
A better looking wider angle from rammb geocolour  https://col.st/SUTyp
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on January 27, 2020, 12:59:18 PM
Amazing, you can see the Atlantic current splitting here (see GIF below). One moving north of Svalbard, the other takes a left turn, towards north Greenland.

(https://www.researchgate.net/profile/Harald_Gjosaeter/publication/321050811/figure/fig1/AS:560528550109184@1510651828144/A-Details-of-Fram-Strait-and-Svalbard-archipelago-including-bathymetry-main-Atlantic.png)

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 27, 2020, 02:55:39 PM
Nice. I expect we will see more of that over the next couple of days. This paper noted on the mosaic thread suggests there may be a small current through the Yermak Pass..

https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2016JC012391
Quote
Regional circulation schematic of Atlantic Water inflow in Fram Strait and Nansen Basin, west and north of the Svalbard Archipelago following Sirevaag and Fer [2009] and Polyakov et al. [2012]. Dashed arrows represent uncertain Atlantic Water pathways around the Yermak Plateau and across the Plateau through the Yermak Pass
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on January 27, 2020, 03:08:38 PM
I'll keep an eye on it! :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on January 28, 2020, 03:44:52 PM
I'll take a punt at this
(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2906.0;attach=142107)
20m suggests inhibited turbulence above that so average ice depth 2-3m, let's guess 0-5m with ridges and leads. So plenty of freezing and salt being excluded by the ice formation, the denser water it takes down is at -1.8. below 20m turbulence increases and temp rises. Suggests flow beneath the ice and the alignment of features suggests waves?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on January 28, 2020, 05:10:17 PM
Thanks johnm33. Better scale on salinity with this chart also legend is not obstructive. It's a shame 75m data is so patchy.
Posted O1 chart as it has better 75m data
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 02, 2020, 11:04:52 PM
Heat loss in the Laptev Sea, https://go.nasa.gov/2RSLf44 , jan14-feb1
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 06, 2020, 07:41:43 PM
From the rammb thread
Now that polar night is descending on the arctic, it's time to switch to band I04, shortwave IR discerns temperature.
link to location (https://rammb-slider.cira.colostate.edu/?sat=jpss&z=5&im=24&ts=1&st=0&et=0&speed=130&motion=loop&map=1&lat=0&opacity%5B0%5D=1&hidden%5B0%5D=0&pause=20191009094722&slider=-1&hide_controls=0&mouse_draw=0&follow_feature=0&follow_hide=0&s=rammb-slider&sec=northern_hemisphere&p%5B0%5D=band_i04&x=16598&y=13956).
North of Svalbard/Yermak Plateau. The (hopefully) never ending battle between sea ice and the warm west spitzbergen current
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 07, 2020, 01:19:38 PM
chukchi export. Ice movement revealing underlying current or bathy perhaps. ctr
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on February 08, 2020, 05:39:13 PM
https://www.nature.com/articles/s41467-020-14449-z

Uniquorn, Here is a very good new article in Nature that is open access. Hat tip to Notadenier.

It explains a lot about how 2007 was transformative in how the Beaufort gyre has operated over the whole period since. It also shows changes with upwelling / downwelling strength during 2012 that might help explain what happened that year besides the GAC.

ps. Have you been looking at ITP 114 ? 

A very pregnant pig starts to look kinda like the t/s contours chart for 114.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 08, 2020, 08:24:59 PM
Thanks Bruce Steele, who would have thought eddies were so important?
here are the temp/salinity charts, 7-200m
https://www.whoi.edu/page.do?pid=165196
microcat1 at 5m depth
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 08, 2020, 09:05:55 PM
caption for image below from Nature (https://www.nature.com/articles/s41467-020-14449-z)
Quote
a Before and b after 2007, including the wind work, W (comprised of atmosphere-ocean, Wao, and ice–ocean, Wio, components), available potential energy (APE), and eddy dissipation, Weddy. The atmosphere and ocean circulations are illustrated by ua and ug, respectively. The size of the arrows/vectors represents their relative strength. The loss of sea ice after 2007 led to increased wind energy input to the BG, increased APE, and increased energy dissipation and freshwater stabilization by eddies.
Quote
Implications for the changing Arctic
Increases in the eddy diffusivity and increased mixing by eddy activity in a more energetic Arctic Ocean is also expected to enhance vertical transport of warm Atlantic water, with consequences for sea ice growth and mixing of biogeochemical tracers.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 08, 2020, 09:50:07 PM
Ran the numbers on itp113 also. https://www.whoi.edu/page.do?pid=165156
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 12, 2020, 09:47:20 PM
a rough and ready view of ascat, jan1-feb11 (no clean up, bad labelling)
The beaufort arch appears to have stalled. Hopefully normal service will be resumed in a couple of days.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 16, 2020, 09:49:51 PM
or not
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 17, 2020, 01:32:19 PM
osisaf drift, beaufort, sep21-feb15
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 21, 2020, 02:54:07 PM
I find it particularly interesting that the leads and apparent wave structures move through the ice rather than with it, the PS' slow progress is the best indication of this I've seen. The emergent double features indicates an acceleration?
Long version probably off topic for the mosaic thread.
Kaleschke Sic Leads, oct1-feb20 for further perusal. Lead motion likely wind based, will try a nullschool overlay sometime.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on February 21, 2020, 04:30:51 PM
OT yes I was hesitant,  but without a more or less stationary PS it looks like the ice is moving, whereas it's stillness suggests waves moving beneath the ice.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Tor Bejnar on February 21, 2020, 04:40:07 PM
Watching where the "pole hole" drifts in Uniquorn's MP4, it seems it tended to be part of the "Beaufort Gyre" in 2019 and generally part of the "Transpolar Drift" (and heading toward Fram Strait) in 2020.  (Lucky for the PS!)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Glen Koehler on February 21, 2020, 08:08:29 PM
osisaf drift, beaufort, sep21-feb15

Thanks Uniquorn.  The changing directions and strengths of the Sept 21- Feb 15 drift observations looks more random than I expected.  I expected to see a consistent pattern of clockwise drift. 
   Is that a typical Sept - Feb drift pattern? 
   Does that view represent the famous Beaufort Gyre or is it just a subset of the larger system?
   Is there a seasonality for the Beaufort Gyre, i.e. is it more consistently clockwise during the melt season?

    PS In looking up "osisaf" (=Ocean and Sea Ice Satellite Application Facility), I found list of acronym definitions at http://www.osi-saf.org/?q=content/acronyms-and-links (http://www.osi-saf.org/?q=content/acronyms-and-links).  Most of the acronyms in that list are too narrow, technical. or not directly relevant ASI to add to the ASIF acronym list, but interesting to look through.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 21, 2020, 10:58:20 PM
Great questions Glen Koehler. My apologies, osisaf low res drift is here (http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2018&month=01&day=07&action=Today&prod=LR-Drift&area=NH&size=100%25) and goes back to 2014 I think, but I only have data from 2019.
There are some mercator model animations upthread showing the beaufort ocean gyre. Since I've been paying attention (2016ish) no ice has completed the circuit but the arc usually continues moving around the coast. Sorry, typing text is not my strong point.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Glen Koehler on February 22, 2020, 12:41:43 AM
osisaf low res drift is here (http://osisaf.met.no/p/osisaf_hlprod_qlook.php?year=2018&month=01&day=07&action=Today&prod=LR-Drift&area=NH&size=100%25)

    Thanks for that link.  The maps with arrows only go back to 2016 for most of the months and days I looked at.  But from January 2017 to present (but 2015 or 2016 for some month-dates), there is a map for every month and date. 

   Bouncing around from year to year for early, mid, and late days of the month for most of the months of the year gives me the impression that the drift pattern frequently changes greatly over 10-day spans.  But while the pattern is highly variable across the different months and dates, I think if you summarized it all (and somebody no doubt has) you would see a fairly strong average pattern of the clockwise motion within the Pacific side of the Arctic Ocean.  What changes most often is the size, and east-west placement of the rotation.  Thus, the drift direction and velocity for any single point would be more highly variable than the larger pattern overall.  But also true that in some images, there is a completely different pattern, or no pattern at all!

    My guess is that the variation in Uniquorn's OSISAF Sept 2019-Feb 2020 animation is more random and chaotic than the average of what I saw in my quick overview of 2017-2019. 

      So the "answers" to my questions become:
Is that a typical Sept - Feb drift pattern?
     With respect to the Sep 2019 - Feb 2020 anmiation -- No.  For the Pacific side of the Arctic (which is bigger than the Beaufort Sea of course), there is, overall, a fairly consistent pattern of clockwise rotation that heads westward along Alaska and Siberian coasts then turns back towards the CAA about halfway across the Arctic Ocean.

   Does that view represent the famous Beaufort Gyre or is it just a subset of the larger system?
   My overview of the 2017-2019 drift maps was for a much larger area (= the entire Arctic Ocean) vs. the more restricted area in Uniquorn's animation.  So the answer is again "No".  I think the area covered by the animation is smaller than the Beaufort Gyre area.  My impressions about the drift pattern stated above are for the Pacific side of the entire Arctic Ocean, not just the Beaufort Sea.

   Is there a seasonality for the Beaufort Gyre, i.e. is it more consistently clockwise during the melt season?
     Based on a superficial quick overview of the drift maps from 2017-2019, the clockwise Gyre pattern seems more consistent in Nov - April, and less consistent in May - Sept.  September seemed to be the month with the least consistent clockwise rotation - gyre pattern.  But caveat emptor - these are just impressions, absolutely zero analysis! 

     There are probably multiple published studies that make these rube-a-mentary impressions unnecessary and may show just how wrong such impressions can be.  I only looked at 3 days a month for 3 years, and skipped a few of those month-date combinations.  I don't have time to look for those articles, but if you know of one, please share.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 22, 2020, 01:24:36 AM
this might help - ascat2010-2019 - temporary post as it is large, pls download
removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 22, 2020, 10:33:14 PM
A rammb look at the large low concentration leads north of Greenland (north is left).
It's a shame itp116 (https://www.whoi.edu/page.do?pid=164836) profiler is dead.
https://go.nasa.gov/38RQqHM feb16-22  ctr

rammb update https://col.st/rAYkY  morbid fascination
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 24, 2020, 12:22:55 PM
Kaleschke sic leads overlaid onto gmrt bathymetry (https://www.gmrt.org/GMRTMapTool/np/), feb15-24.
Tech note - used contrast and unsharp mask to keep some greys
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on February 24, 2020, 12:56:08 PM
It's a shame itp116 profiler is dead.

 :'(

How confident can we be it's actually dead? I mean, is there a chance it's coming back again?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 26, 2020, 02:01:16 PM
If it 'comes back' from dead we can be confident it's alive ;)

Follow up on the large low concentration leads north of Greenland.
https://go.nasa.gov/32tcuWI , feb16-26, Kaleschke SIC leads inset. There are some differences as refreeze progresses.  ctr
Beginning to see a pattern in the wave like low concentration lines from previous years
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on February 26, 2020, 02:42:03 PM
If it 'comes back' from dead we can be confident it's alive ;)

That's not 'it's dead for good' as an answer. I guess i'm staying optimistic then. ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 26, 2020, 09:05:22 PM
ascat, north of greenland, day51-56, forward and back. Fram/FJL gap intake drift extends as far as the Lomonosov ridge (vertical line to left of pole hole), temporarily.
Ice slips more easily on higher salinity water? or more turbulence along the ridge?

added an avi of ascat, lomonosov ridge area, 2010-2019 for those few that would like to see if there is a similar previous occurrence since 2010. mp4 quality after conversion and compression not really good enough.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Glen Koehler on February 27, 2020, 07:38:45 PM

Speaking of gyres ...
https://insideclimatenews.org/news/26022020/climate-oceans-weather-fishing-gyres-gulf-stream-sea%20level (https://insideclimatenews.org/news/26022020/climate-oceans-weather-fishing-gyres-gulf-stream-sea%20level)

   I suppose at ca. 1 km per year it won't happen anytime soon, but looking at the north end of that North Atlantic gyre loop in the map included with the article
https://insideclimatenews.org/sites/default/files/styles/colorbox_full/public/image_large/OceanGyres529px.png?itok=yoTQ6XPg (https://insideclimatenews.org/sites/default/files/styles/colorbox_full/public/image_large/OceanGyres529px.png?itok=yoTQ6XPg)
makes me wonder if someday it will loop over Greenland and go straight across the Arctic.  That would be "Atlantification" on steroids.


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Glen Koehler on February 27, 2020, 07:55:19 PM
Edited quote
Arctic ice sets speed limit for major ocean current
Quote
The Beaufort Gyre is an enormous, 600-mile-wide pool of swirling cold, fresh water in the Arctic Ocean, just north of Alaska and Canada. In the winter, this current is covered by a thick cap of ice. Each summer, as the ice melts away, the exposed gyre gathers up sea ice and river runoff, and draws it down to create a huge reservoir of frigid fresh water, equal to the volume of all the Great Lakes combined.

 ..... Scientists at MIT have now identified a key mechanism, which they call the "ice-ocean governor," that controls how fast the Beaufort Gyre spins and how much fresh water it stores.

"If this ice-ocean governor goes away, then we will end up with basically a new Arctic ocean," Marshall says......
 
The research paper (https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2018GL080171?referrer_access_token=rRLNlYJSW-oXwqMzQfGOGsOuACxIJX3yJRZRu4P4ervn61VIykWY5YWIytNp6u1vnBrwhD7pPGe-9rb1xpZHbqzR9Y1mNbjHw_NG4RlgTm-wCZn94UviiAQJMP4hFGJK)
If the Beaufort Gyre can reach the Atlantic Ocean, the reverse is not so far-fetched.  I guess this is what comes with an increasingly "Equable climate" where the poles are no longer isolated from the midlatitudes.  Which does not bode well for ASI longevity.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on February 29, 2020, 02:43:48 PM
Beaufort ice drift relatively static at the moment.
update on Kaleschke SIC leads, feb22-29, ctr.
Anticyclone building up over the pole will likely disrupt the pattern a bit
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 04, 2020, 11:04:01 PM
4 mosaic Vbuoys measuring temperature and salinity  down to ~125m
Buoy type:   DTOP Ocean Profiler
https://data.meereisportal.de/download/buoys/2019V1_300234067068380_ocean_proc.csv
https://data.meereisportal.de/download/buoys/2019V2_300234067064490_ocean_proc.csv
https://data.meereisportal.de/download/buoys/2019V3_300234067064370_ocean_proc.csv
https://data.meereisportal.de/download/buoys/2019V4_300234067066520_ocean_proc.csv

unfortunately latest data is feb17. Maybe look at them later.


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 17, 2020, 09:14:08 PM
update on the low concentration ice north of greenland using Kaleschke SIC leads. ctr
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on March 17, 2020, 10:31:34 PM
must take a look a the beaufort again soon. Here is whoi itp114
https://www.whoi.edu/page.do?pid=165196
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on April 10, 2020, 07:57:22 PM
uniquorn your latest ascat (https://media.giphy.com/media/j5QdumvVPsTg6G59oM/giphy.gif) showed ice lifting off the CAA and moving north, somewhat unusual so i took a look at Beaufort/Hycom (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortictn_nowcast_anim30d.gif) which agrees and seems to show the whole ice pack moving in sync. but the strength gif shows enormous amounts of [?] internal wave activity which seem to be driven by surges in from the Pacific side, obviously i think tidal, but smashing any coherence the ice may have had on that side.
(https://media.giphy.com/media/LjzCC9A09AQqLZde3t/giphy.gif)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 10, 2020, 11:11:57 PM
Not that unusual but CAA coastal ice is probably weak this year. Lift off documented here (https://forum.arctic-sea-ice.net/index.php/topic,2839.msg258548.html#msg258548)
Comparing the hycom gif (model based) with amsr2-uhh and https://go.nasa.gov/3ebOD3l and looking at nullschool (https://earth.nullschool.net/#2020/04/04/1800Z/wind/surface/level/orthographic=-53.73,85.62,1452), I think the lift off is wind based.
Not sure how to analyse the ocean areas. sic-leads might help but that is currently unavailable. Rammb has potential for showing tidal movement in localised areas but how to show  the effect of internal waves?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 10, 2020, 11:59:00 PM
which seem to be driven by surges in from the Pacific side
Possibly all wind driven? Unusual that we have had almost zero easterlies along the alaskan beaufort coast. Nearly all cyclone and westerlies, building up the compressive strength on the CAA coast. Then southerlies arrive over the CAA causing lift off, pressure is released, then the ice 'bounces' back. Thickening by ridging, better than nothing, but not the same as fast ice.
On top of that though, much of the ice is moving eastward to the Fram, leaving unridged areas newly refrozen. Probably some up/downwelling going on. I don't know which.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on April 11, 2020, 01:14:20 AM
(https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/beaufortstrength/nowcast/strength2020040212_2020040300_930_beaufortstrength.001.gif)
'Internal Waves' On the left of the image waves at depth rotating/overturning aligned to their direction of movement [with energy gained by approaching the axis] create elongated 'hills' as they pass, but whether they are rolling towards [accelerating] or against the flow is opaque, but either way temporarily thinning the ice above them. Then two waves of similar power on the right again with ?semitones? . In between where the the colours transition through green much smaller but still huge waves that persist for thousands of miles, and somehow are more or less orthogonal to both systems which flank them. Almost as if the 'electricity' on the left caused orthogonal waves of magnetism to move right and that in turn induced more 'electricity' to flow far to the east. In some sense the wave has it's 'natural' speed but i wonder if the energy gained as the axis is approached travels closer to the speed of sound in water slowed only by it's spiralling motion.?
Yes agreed the lift off CAA and movement north was probably wind driven, indicating as you say weak ice, but elsewhere the winds have been too fickle to be a convincing factor.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on April 12, 2020, 06:16:52 AM
'Internal Waves' On the left of the image waves at depth rotating/overturning aligned to their direction of movement

I'm a bit unclear on this - are you claiming that waves are propagating large amounts of water in a rotating / overturning movement at depths under the ice, and still close enough to the ice to actually affect the surface sufficiently for the resulting patterns to be seen from space?

If so, have you considered the halocline? Is that still in place? Are there any buyos that show this wave motion?  The Arctic contains about 300 billion tons of water, what proportion of this do you think is engaged in rotating / overturning / surging waves big enough to leave patterns visible from space?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on April 12, 2020, 02:19:28 PM
"claiming" well more a suggestion, funnily enough when i'd slept on it i woke up with the idea that the ones on the left were more likely tidal surges propagating across the shelf, they'd be about 10k wide and maybe .3/.5m high just enough to stretch the ice but not to open it up and that enhanced by the overturning, like? (http://chaosbook.org/tutorials/Movies/bigbox_rand.mp4) so picking up angular momentum as they approached the axis/pole, accelerating energy to the east and instead of a semi-tone an induced reverse wave?
The two major waves on the right though are less ambiguous, maybe they're what's showing up as off the scale intrusions at depth on bouys (https://www.whoi.edu/page.do?pid=163376) 104/5 t+s contours
(https://www.whoi.edu/itp/images/itp104dat3.jpg)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 12, 2020, 04:05:37 PM
Unfortunately that was itp104's last profile on aug29 last year. It is still providing drift data though, which in itself is unusual.
itp105's profiler data stopped on the same day, and is also drifting east.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 12, 2020, 04:31:07 PM
While we are looking at whoi buoys. itp116 (https://www.whoi.edu/page.do?pid=164836) is just about to enter the fram strait, though south-easterlies are forecast that may hold it up for a while.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on April 15, 2020, 10:17:25 PM
'unfortunately' thanks, even dumber than it looked, I actually spent some time oct/nov trying to figure out why.
itp94 does the salinity indicate A.W. ?
(https://www.whoi.edu/itp/images/itp94dat3.jpg)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 20, 2020, 09:17:04 PM
Quote
itp94 does the salinity indicate A.W. ?
Maybe not since they have been passing over the deepest part of the basin. The data looks different to the Obuoys. Will look again. I'm more familiar with whoi itp's than Obuoys.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 20, 2020, 09:24:44 PM
Mercator 318m salinity, Pacific side, sep2018-apr2019 (60fps, 6sec/yr)

atlantic side here (https://forum.arctic-sea-ice.net/index.php/topic,3030.msg260789.html#msg260789)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 21, 2020, 12:15:58 PM
Reposting from here (https://forum.arctic-sea-ice.net/index.php/topic,3017.msg260872.html#msg260872) so it doesn't get lost too quickly. I hope it is ok to reproduce the images here also.
Quote
For our discussion here we are interested about the formation of the leads, why and where they form:

Multiplex imaging with satellite cluster produces images of entire Arctic Ocean cloud-free during sunlight season, including the infrared and UV-scanners that identify sources or ships' heat or electric lights, whatever. On CV page 10 you can see how the continuous breakwater pulse propagates within the Arctic Ocean and weakens the sea ice from the estuary onwards. (The large image on the top.) Typically ultimate "C", penultimate "B", and antepenultimate "A" ice floes form from the Russian coast running their weakened seams perpendicularly to Canada where the ultimate "C" typically hits at the Western Last Sea Ice Area (Western - LIA) where the turning process causes opposite stress point, thus segregating the ultimate "C" and penultimate "B". There are two of these, but only one C/B is shown on my CV, both of them would be interest to this discussion.

There are couple other processes on the Arctic Ocean:

Page 8 The antepenultimate "A" facing the Atlantic runs on its own with the alternating zebra patterns of green and white on this image (result of breakwater waves or cells rolling on shallow sea).

The density differentials form the colours here as the river water from Russia moves along and rolls a bit like Swiss roll on its way to deep water near Fram Strait. The high density water is white as sea surface is lower than the ocean median ice surface (the median lines are highlighted on image for clarity), the low density river water is green due to it representing higher than the ocean median ice surface (due to its being less saline, it needs higher water column than saline water to keep ocean surface at equilibrium pressure).

The white colour forms over the dense water where ocean surface is lower than median and fills with drift snow. The green colour forms on the crest that is higher and without the drift snow that accumulates on troughs. The snow accumulation further amplifies the effect anchoring even more snow over the dense, saline rollers.

Because of this constant rolling of Swiss rolls between the ocean floor and its surface (sea ice), there is an overall current which has higher gravity potential and faster forward movement on surface, this then marks the boundary between antepenultimate "A", and penultimate "B" as the B flows slower than A.

These things have also changed over the years as ice in overall has pulverised and not been forming uniform films, but overall show the effect of North Asian rivers discharging onto the Arctic Ocean and forming weak points by supply of warmer water and its mixing and dragging heat out from warmer waters beneath - then maintaining a thinner ice along a narrow channel which presses against Canada (Western Last Sea Ice Area, by splitting the sea ice C/B and B/A, with B/A junction also running at different speed.

The differential movement on p. 8 is shown by 12 perpendicular secondary cracks (highlighted) on the main B/A crossing from Komsomoletski Island to Ellesmere Island.

Page 9 focuses on vortices or breakwater cells that fall into the deep channel, warm up aggressively and surface like cumulus cloud with the centre of pancake elevated with edges bending down and below median and filled by snow. These curving sea ice "spaghetti" edge formations are rare in comparison of the rectangular edge formations caused by breaking ice and re-freezing ice.

The rest of my Curriculum Vitae outside pages 8, 9, 10 are irrelevant to this forum.
https://www.academia.edu/5859691/Curriculum_Vitae_for_Exploration_and_Research
From the CV
Quote
The “zebra” pattern of green and white
stripes across the Arctic Ocean are a result of tiny sea ice surface level variations as the riparian water discharges from Siberia mix gradually with the saline sea water in the Arctic Ocean. The advancing breakwater currents create a complex web of turbulent flow currents. Those sea ice areas where the breakwater waves are cresting have only little drift snow accumulating, while the wave troughs have accumulated a much thicker snow blanket and appear, therefore, whiter

The Komsomoletski –Ellesmere Island River Ice “barrier” (a group of thirteen parallel leads in sea ice) used to form along the two sea ice currents that moved at different speeds. The sea ice that rests on breakwater current on the Kara Sea moves faster than the Arctic Basins' stiff multiyear circumpolar ice current. As the air temperatures on the North Pole are well below freezing, the two sea ice areas which move at different speeds appear as conjoined but because of their different speeds, the sea ice currents soon build up stresses perpendicular to the “barrier” line when the slow ice in the Arctic Basin cannot keep up with the pace of thinner and faster moving sea ice found on the Kara Sea

The computer-processed Arctic Ocean sea ice images where the cloud cover has been removed shows further large scale structures. Some of these have rectangular shapes while others have rounded shapes.
 It is well known from diving expeditions that there is a plenty of light under the sea ice in the Arctic Ocean and the sea ice does not completely block the sunlight. What I have done is to search for this rebound radiation, light which is coming from beneath the sea ice. Where the sea ice cover is over one year old the sea ice appears whiter, whereas the previous winter’s sea ice appears much darker as it is thinner.
 The curved ice boundaries in the Arctic Ocean’s ice, the “spaghetti” patterns and the elevated “pancakes” both form when the breakwater waves fall off the shallow continental shelf into a deepwater trench near the North Pole. The breakwater sinks in a warm and saline surroundings and curls into vertical eddies. These initially travel southwards when they start sinking, but once they have sunk deep enough their movement reverses to northward. Due to the lack of salinity, the warmed eddies begin a rapid ascent. Once such a warmed-up vertical breakwater eddy hits the ocean’s surface it forms a pancake-like elevated region which is visible on the sea ice. The above processes represent only the Atlantic end of the Arctic Ocean and there are different processes occurring on the rear end of the Arctic Ocean due to the stiff and much thicker multi year ice

The rear end of the Arctic Ocean as seen in this computer-processed multicolor image of the Laptev Sea is predominantly made of thick multi-year sea ice. The warm riparian discharges travel towards the Arctic Basin and are releasing heat on their way from the river estuaries. The spring time warm riparian discharges appear tunneling under the sea ice and thinning it. Due to the prevailing sea currents such as the Beaufort Gyre, the sea ice breaks along the sections of thinned sea ice where long leads are formed

Once a lead has been triggered in the Arctic Ocean’s ice by a flow of the warm river water, the splitting of sea ice progresses unstopped like a glass split.
 The leads that form from the east Russian rivers rapidly split the sea ice across the ocean all the way to Canada where the unhindered Arctic Ocean’s ice cover finally ends due to the topographic constraints laid down by the Canada’s Nunavut Archipelago which divides the ocean to numerous sounds.

 These are just a selection of my work at the Frozen Isthmuses’ Protection Campaign to understand and protect the Arctic Ocean’s ice better.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 21, 2020, 11:05:37 PM
itp94 does the salinity indicate A.W. ?
Yes. I think it does. Obuoy 2019O1 is significantly redder than hycom SSS (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arcticsss_nowcast_anim30d.gif) on apr1 at ~85N

time                               Lat         Lon   salinity_10m   20m     50m     75m    salinity_100m
2020-04-01T00:00:00   84.941   16.531       34.07   34.07   34.08   34.27   34.32



%ITP 94, profile 327: year day longitude(E+) latitude(N+) ndepths
2020  111.23177    15.4621  84.6432  377
%year day pressure(dbar) temperature(C) salinity oxygen(umol/kg) turbidity(10e-4/m s/r) chlorophyll(ug/l) cdom(ppb) par(V)
2020  111.23222    8   -1.8679   34.1219    8.7613    0.7493    0.0803    2.4300    0.8088
2020  111.23228   10   -1.8678   34.1220    8.7664    0.7493    0.0657    2.5200    0.7846
2020  111.23236   12   -1.8678   34.1219    8.7726    0.7493    0.0803    2.3850    0.7410
2020  111.23247   14   -1.8678   34.1220    8.7826    0.7738    0.0621    2.3400    0.6976
2020  111.23258   16   -1.8681   34.1217    8.7913    0.7493    0.0766    2.2950    0.6541
2020  111.23269   18   -1.8682   34.1217    8.7915    0.7575    0.0657    2.4750    0.5883
2020  111.23278   20   -1.8681   34.1217    8.7901    0.7331    0.0657    2.4300    0.5458
2020  111.23286   22   -1.8681   34.1217    8.7886    0.7656    0.0803    2.3850    0.5060
2020  111.23297   24   -1.8681   34.1217    8.7961    0.7575    0.0657    2.4750    0.4527
2020  111.23306   26   -1.8679   34.1217    8.8065    0.7493    0.0803    2.4300    0.4222
2020  111.23314   28   -1.8681   34.1219    8.7968    0.7575    0.0766    2.4300    0.3691
2020  111.23322   30   -1.8679   34.1217    8.8199    0.7493    0.0730    2.6100    0.3531
2020  111.23330   32   -1.8679   34.1219    8.8174    0.7901    0.0657    2.4300    0.3272
2020  111.23339   34   -1.8679   34.1220    8.8050    0.7493    0.0876    2.5200    0.2615
2020  111.23347   36   -1.8678   34.1220    8.8229    0.7656    0.0693    2.4300    0.2394
2020  111.23358   38   -1.8677   34.1219    8.8267    0.7656    0.0803    2.5650    0.1879
2020  111.23367   40   -1.8677   34.1219    8.8108    0.7493    0.0584    2.5200    0.1712
2020  111.23374   42   -1.8676   34.1219    8.8324    0.7493    0.0766    2.4300    0.1188
2020  111.23383   44   -1.8676   34.1219    8.8309    0.7819    0.0949    2.3400    0.0913
2020  111.23392   46   -1.8675   34.1218    8.8377    0.7412    0.0693    2.3850    0.0821
2020  111.23402   48   -1.8674   34.1220    8.8393    0.7738    0.0766    2.4300    0.0389
2020  111.23411   50   -1.8673   34.1221    8.8492    0.7493    0.0657    2.3400    0.0066
2020  111.23420   52   -1.8671   34.1221    8.8337    0.7656    0.0876    2.4300    0.0021
2020  111.23427   54   -1.8671   34.1225    8.8527    0.7819    0.0657    2.5200    0.0037
2020  111.23436   56   -1.8668   34.1229    8.8511    0.7656    0.0693    2.5200    0.0039
2020  111.23447   58   -1.8664   34.1239    8.8455    0.7575    0.0730    2.5650    0.0039
2020  111.23455   60   -1.8652   34.1277    8.8478    0.7493    0.0730    2.3400    0.0027
2020  111.23464   62   -1.8626   34.1327    8.8575    0.7575    0.0766    2.3850    0.0031
2020  111.23472   64   -1.8561   34.1459    8.8668    0.7493    0.0657    2.4300    0.0027
2020  111.23480   66   -1.8426   34.1546    8.8804    0.7493    0.0657    2.3400    0.0050
2020  111.23488   68   -1.8262   34.1596    8.8738    0.7493    0.0803    2.3400    0.0049
2020  111.23497   70   -1.7971   34.1726    8.8561    0.7412    0.0657    2.3850    0.0033
2020  111.23508   72   -1.7561   34.1918    8.8527    0.7331    0.0693    2.3400    0.0031
2020  111.23516   74   -1.6809   34.2265    8.8310    0.7819    0.0657    2.0700    0.0024
2020  111.23525   76   -1.6183   34.2573    8.8171    0.7493    0.0657    2.2500    0.0042
2020  111.23534   78   -1.5876   34.2789    8.8020    0.7493    0.0584    2.0700    0.0037
2020  111.23541   80   -1.5753   34.2892    8.7717    0.7656    0.0548    2.2050    0.0026
2020  111.23553   82   -1.5664   34.2976    8.7516    0.8878    0.0657    2.1600    0.0032
2020  111.23561   84   -1.5591   34.3063    8.7267    0.7331    0.0438    2.1600    0.0042
2020  111.23569   86   -1.5549   34.3114    8.7032    0.7412    0.0584    2.0250    0.0027
2020  111.23578   88   -1.5511   34.3167    8.6841    0.7168    0.0657    2.0700    0.0022
2020  111.23586   90   -1.5428   34.3249    8.6676    0.7331    0.0548    2.0250    0.0033
2020  111.23594   92   -1.5402   34.3306    8.6527    0.7168    0.0511    1.9800    0.0046
2020  111.23602   94   -1.5388   34.3357    8.6464    0.7575    0.0474    1.8900    0.0049
2020  111.23614   96   -1.5326   34.3395    8.6215    0.7656    0.0548    1.9800    0.0048
2020  111.23622   98   -1.5275   34.3424    8.6197    0.7331    0.0511    1.9800    0.0022
2020  111.23630  100   -1.5286   34.3453    8.6101    0.7493    0.0474    1.9350    0.0046
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 21, 2020, 11:52:10 PM
Meanwhile in the Beaufort, whoi itp114 (https://www.whoi.edu/page.do?pid=165196) is also experiencing a higher salinity event. Temperature also looks higher but it's at 44m depth, +1.28C. Microcat2 is at 6m depth.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on April 22, 2020, 10:32:54 AM
Looking at Beaufort (https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/beaufort.html) strength there appears to be some surface[?] turbulence penetrating from the north, taken with the local cracks on Worldview, is this what a freezing event looks like? Dense brine dropping and causing upward mixing of warmer layers. Where exactly was it on 430 and 452 for instance and does this explain the black/white anomolies?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on April 22, 2020, 12:06:16 PM
Where was it? Download the zip file (http://ftp://ftp.whoi.edu/whoinet/itpdata/itp114grddata.zip) and take a look.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 08, 2020, 09:31:07 PM
noted (https://forum.arctic-sea-ice.net/index.php/topic,3017.msg263362.html#msg263362) for the smos reference
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 08, 2020, 10:42:07 PM
looking at some high pressure passing over Fram to Laptev.
Default ascat day104-124, medium/heavy contrast, A-team interferometry (https://forum.arctic-sea-ice.net/index.php/topic,1259.msg143664.html#msg143664) (high volume users only)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 09, 2020, 12:08:58 AM
maybe I cropped too close
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 11, 2020, 10:16:30 PM
Laptev ice over bathymetry, https://go.nasa.gov/3cnAUFb, may11. click to run
Similar cause to the FJL/Svalbard side of the basin perhaps.
added a short rammb, nothing conclusive.  ctr
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 12, 2020, 08:43:35 PM
Surprised by the amount of drift difference when looking at the mosaic buoys I thought I'd check using ascat interferometry (https://forum.arctic-sea-ice.net/index.php/topic,1259.msg143664.html#msg143664).
Areas which don't move much are grey, those that move more are brightly coloured. Try to ignore the open water (unless it means something to you)

Quote
Take 4 filmstrips of daily ascats and cut the first image off the second strip, the first 2 images off the 3rd strip and the first 3 images off the 4th strip.
Then lie the the first and second strips on top of each other from the left and save the difference as a new film strip. Call it the 1day difference strip. (In this case we use gimp grain extract)
Do the same to the first and third strips. Call the new strip 2day difference strip.
Then do the first and 4th strip to get the 3day difference strip.
Now we want to overlap all 3 difference strips so we compose a new strip by making each of the 3 strips red, green and blue and combining them into a colour image.
Areas which don't move much will combine the 3 colours to grey, those that move more will be more brightly coloured depending on the daily differences.

Ascat shows a lot of movement over open water, this can be masked out using an amsr2 mask but that takes longer.

2019 day280 to 2020 day132 most of the freezing and melting season up to now
7.5MB
Please be aware that swath rotation artifacts are amplified using this method
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 13, 2020, 09:49:19 PM
following up on post582 above (https://forum.arctic-sea-ice.net/index.php/topic,2417.msg263765.html#msg263765), here is a heavy contrast animation of ice over the laptev side of the Nansen Basin shelf. https://go.nasa.gov/2y4eVo4, may4-13
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 16, 2020, 10:22:24 PM
mercator sea surface height, jan1-may15
Remembering that bering strait depth (https://www.gmrt.org/GMRTMapTool/np/) is max ~53m so volume is not huge.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 17, 2020, 12:17:21 AM
following up on post 539 (https://forum.arctic-sea-ice.net/index.php/topic,2417.msg248647.html#msg248647), not sure about eckman pumping but there is good evidence of eddies shown in thin ice in the barents at the moment, https://col.st/tvlWA
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 17, 2020, 03:02:32 PM
mercator current, 34m depth, jan1-may16
scale is m/s
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 18, 2020, 11:33:36 PM
following up again on laptev/nansen shelf, https://go.nasa.gov/36blX6R may11-18. Possible second low concentration line follows the first. Hint of previoius line. click to run
mercator salinity 34m, jan1-may17
forgot scale
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on May 19, 2020, 11:18:02 AM
itp94 (https://www.whoi.edu/itp/images/itp94dat3.jpg) gives some indication that there may be a [+/- 3 day resonance] standing wave in the depths of Amundsen, it shows more strongly in the occasional alternative T+S contours image  (https://puu.sh/FFkVA/ae6f617e70.jpg)
I'm guessing that these waves, if that's what we're seeing, would bounce back off the shelves giving us cross waves and 'point' surface melt where they cross close to 900.
 These are from the far end of the basin and it may be that the waves are moving in opposite directions through one another?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 19, 2020, 04:32:46 PM
artifact of the profiler only descending to full depth of 800m every 2? days, probably to extend battery life (or maybe they are more interested in the top 200m for this expedition).
There are some interesting temperature layers there below 200m though.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on May 24, 2020, 07:30:37 AM
We have water temperature readings from microcat data for ITP 113 and 114 at 5 and 6 meters as well as Sami water temperature data at 6 meters for ITP 117 and 118 . They are all in the Beaufort and every buoy showed water temperature increases at 5-6 meters over the last ten days.
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 24, 2020, 10:51:27 AM
Thanks Bruce Steele. 3 of them may be affected by proximity to the shelf or possible current into Mclure Strait.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on May 31, 2020, 07:11:30 PM
Current or eddies in the Kara Sea. amsr2-uhh, may10-30
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 03, 2020, 10:09:29 PM
We have water temperature readings from microcat data for ITP 113 and 114 at 5 and 6 meters as well as Sami water temperature data at 6 meters for ITP 117 and 118 . They are all in the Beaufort and every buoy showed water temperature increases at 5-6 meters over the last ten days.
 
You may be onto something Bruce. whoi itp113 microcats, 5m and 6m. 0.1degC temperature spike. Smaller spike on itp114.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on June 03, 2020, 10:50:19 PM
Uniquorn, We have microcat data from ITP Whoi 107 from last year. Scale is different but it looks like the freshwater lens in the Beaufort is  catching heat from insolation . Those buoys nearer center of gyre show largest heat gains.

https://www.whoi.edu/page.do?pid=165217
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on June 04, 2020, 12:02:51 AM
Here is a new paper on PAR and how melt season and light availability affect algae under the ice.
Open access
https://www.frontiersin.org/articles/10.3389/fmars.2020.00183/full

“The depth under the sea ice experiencing spatial variability in light levels due to the influence of surface heterogeneity in snow, white ice and melt pond distributions increased from 7 ± 4 to 20 ± 6 m over our study. Phytoplankton drifting in under-ice surface waters were thus exposed to variations in PAR availability of up to 43%, highlighting the importance to account for spatial heterogeneity in light transmission through melting sea ice.”
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 04, 2020, 09:44:30 PM
"Current or eddies" Looks like both, not sure that would've been picked up elsewhere, maybe it's a new phenomenon, certainly seems to indicate a flood of Atl. water[based on it's inertia eastward] rushing down St. Anna, may be pushing it but perhaps the disturbance above above Amundsen towards Lomonosov, the recent surface melt, was caused by this. It appears to be recurring so maybe there'll be a repeat.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 07, 2020, 03:10:19 PM
Current and/or eddies continue. Looks amazing on worldview today.
uni-hamburg amsr2-uhh concentration, st anna trough, may10-jun6.
worldview, terra modis, jun7.   https://go.nasa.gov/3gYCyjo
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on June 10, 2020, 05:37:16 PM
Looks huge
(https://puu.sh/FUNvu/735c6ebf27.jpg)(https://puu.sh/FUNxL/a96cf77364.png)
my interpretation is eddies forced by the Atl. current accelerating down St. Anna, eddies and counter eddies caught up in the trough by Gakel so moving both east and west, both reaching the surface but eastbound with more energy. Not sure that waves reflected by Lomonosov have begun to interfere yet but Bremen amsr2 will lighten up when that happens. Surge of incoming water causing acceleration towards Fram of the layer @75m deep not steadied by contact with ice, stretching the layer above it and opening up the ice. This will also push tidal Atl. water towards CAA and act to force tidal surges in Greenland/Norwegian seas to either short circuit around Iceland or climb onto Barentz shelf to continue the assault.   
What are those two wave forms on the other side? no trace of them elsewhere.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 10, 2020, 09:33:17 PM
my interpretation is eddies forced by the Atl. current accelerating down St. Anna...
Though there was already low concentration ice there, I think yesterday's event is more likely due to rain. Jayw posted a good rammb (https://forum.arctic-sea-ice.net/index.php/topic,2649.msg268054.html#msg268054) showing it.
The concentric circles look like artifacts. Should wait till tomorrow before thinking about them.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 10, 2020, 11:59:08 PM
Curious what might be causing incoming atlantic water to be upwelling. Initial impression is that the saltier water is going down when it has the opportunity.
To clarify, I consider Atlantic water incoming until it begins the return journey to the Fram. Furthest reach is the ESS, west north of Wrangel Island. A quick search found this. I hope you find it helpful.

https://www.ocean-sci.net/14/293/2018/os-14-293-2018.pdf
Quote
Upwelling in the Arctic
In their seminal 2003 paper mentioned above, Carmack and Chapman applied a numerical model to study shelf–basin exchange on the Beaufort Sea shelf and argued that decreased ice concentrations will enhance upwelling in the area.
The argument goes like this: when a thick ice cover lies like a lid on the ocean, it absorbs most of the wind stress instead of transferring it to the underlying ocean. When the ice edge recedes far  enough  north  that  the  shelf  break  is  exposed,  however, the winds can move around the surface waters more easily. Sustained easterlies, for example, will lead to a northward Ekman transport, and where the shelf is shallow enough that it affects surface currents (see Figs. 2 and 3), deeper waters are drawn up to balance the off-shelf transport. This argument was reinforced by a number of studies conducted in the Pacific Arctic (Williams et al., 2006; Schulze and  Pickart,  2012;  Spall  et  al.,  2014;  Arrigo  et  al.,  2014;Lin et al., 2016), which directly extended earlier direct observations  of  shelf  break  upwelling  dating  back  to  at  least the 1980s (e.g. Aagaard et al., 1981). A detailed study (Spallet al., 2014) on the dynamic response during one particularly impressive example of shelf break upwelling in the Chukchi Sea (Arrigo et al., 2014) demonstrated potentially large contributions to primary productivity in that area. The  idea  has  since  caught  on  to  explain  or  project  marine productivity also in other regions of the Arctic Ocean, for example at the Barents Sea shelf break. There it has appeared  both  in  numerous  personal  communications  among the community working with the physical and ecological environment of the Barents Sea and a number of published articles (see e.g. Falk-Petersen et al., 2014; Tetzlaff et al., 2014;Wassmann et al., 2015; Hunt et al., 2016; Våge et al., 2016;Haug et al., 2017). Thus it might appear as if shelf break up-welling is currently being cemented as a universal paradigm to conceptualize the “new” Arctic Ocean where global climate  change  is  taking  us.  We  will  argue  that  some  of  the regional differences cannot be ignored when discussing what governs productivity in the various shelf regions.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Phoenix on June 11, 2020, 01:04:40 AM
This is very interesting stuff uniquorn. Thanks for sharing.

I note the paper's emphasis that there is significant regional difference in upwelling potential and that they specify the shelf under the Beaufort off CA and AK to be the region where this is most likely to be significant.

I'm taking a break from the cryosphere. Thanks for your contribution to the discussion and my understanding of the topic.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on June 11, 2020, 01:15:35 AM
https://www.researchgate.net/publication/339766641_Wind-Driven_Coastal_Upwelling_Near_Large_River_Deltas_in_the_Laptev_and_East-Siberian_Seas

“The Lena, Kolyma, and Indigirka rivers are among the largest rivers that inflow to the Arctic Ocean. Their discharges form a freshened surface water mass over a wide area in the Laptev and East-Siberian seas and govern many local physical, geochemical, and biological processes. In this study we report coastal upwelling events that are regularly manifested on satellite imagery by increased sea surface turbidity and decreased sea surface temperature at certain areas adjacent to the Lena Delta in the Laptev Sea and the Kolyma and Indigirka deltas in the East-Siberian Sea. These events are formed under strong easterly and southeasterly wind forcing and are estimated to occur during up to 10%–30% of ice-free periods at the study region. Coastal upwelling events induce intense mixing of the Lena, Kolyma, and Indigirka plumes with subjacent saline sea. These plumes are significantly transformed and diluted while spreading over the upwelling areas; therefore, their salinity and depths abruptly increase, while stratification abruptly decreases in the vicinity of their sources. This feature strongly affects the structure of the freshened surface layer during ice-free periods and, therefore, influences circulation, ice formation, and many other processes at the Laptev and East-Siberian seas.”


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 11, 2020, 11:30:19 PM
https://www.mdpi.com/2072-4292/8/1/4/htm
Sea-Ice Wintertime Lead Frequencies and Regional Characteristics in the Arctic, 2003–2015
by Sascha Willmes and Günther Heinemann
Quote
3.4. Spatial and Temporal Lead Dynamics
If the lead aggregation is performed for the entire period of investigation from 2003 to 2015, we obtain valuable insight in the general pattern of lead occurrences in the entire Arctic (Figure 5). As in the annual maps, the MIZ as well as the characteristic polynya regions are well represented by high lead frequencies, whereas the opposite is again found for fast-ice regions. The position of the fast-ice edge in the East Siberian Sea is characterized by higher variability than e.g., in the Laptev Sea. Again, the Beaufort Sea is revealed as an area of major lead activity within the pack ice zone (A). Major shear zones and the associated higher frequency of leads are generally found in the proximity of islands and continental coasts. In addition, smaller characteristic features are highlighted in the presented map, e.g., Hanna Shoal, in the Northern Chukchi Sea (B, [23,37]), is clearly revealed as a significant hot spot of high lead frequencies in the presented map. A band of slightly enhanced lead activity that reaches from the central Beaufort Sea to the new Siberian Islands is visible (C) and in the East Siberian Sea, some less known features exhibiting high lead frequencies are indicated north of the Kolyma Gulf (D). They seem to stem from the presence of several small shoals in this region. An enhanced lead activity is also found in the outflow of the Vilkitzky canyon in the western Laptev Sea (E) and in the shear zone east of Severnaya Zemlya (F). In the northwest of Franz-Josef Land, an elongated region of high lead frequencies (G) is also revealed. As the features shown in E and G are probably not connected shear zones, we speculate that they might be promoted by bathymetric effects (see discussion). The region North of Greenland, at the western edge of the Transpolar Drift stream (H) is also characterized by a higher frequency of leads as compared to the surrounding region.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 15, 2020, 05:30:44 PM
For future reference.
The 12z models and 00z EURO the 12z euro isn't out yet have backed off considerably with the dipole in the long range.

Instead of setting up a full or 3/4 dipole the models slide the Eurasian vortex over the pole/Atlantic side and merge it with the GIS vortex which won't budge.

This keeps the torching over the Pacific half.

It's not a good pattern by any means but it definitely is much better than the entire CAB getting the roast.

This kind of thing is what will keep 2020 from passing 2012 in the end.

We'll see

Yep, we've seen this time and again in the last 8-9 years. It's a pattern and I think part of the reason for this strong +PV tendency has been due to a marked increase in low-level baroclinicity and eddy kinetic energy as the mid-high lats warm faster in summer than the basin proper. It is providing a transient negative feedback by preferentially favoring storms over the basin during the summer months (on the cold side of the jet). This retards melt and slows down the year-to-year summer progression. Of course, eventually the warming signal will overwhelm this, but it may take another 20 years to do so (the occasional year like 2016 nonwithstanding). Eventually, increasing warming over land will cause the warm conveyor belts on these storms to start doing enough damage to offset the shielding effect and destroy ice cover anyways. We may end up seeing a fairly long period of not much change -- followed by a quick transient period to sea-ice free, followed by decoupling of the troposphere from the stratosphere in the autumn and subsequent large hits to winter ice volume recoveries. Nakamura et. al's BoE experiments suggested as such a few years back.

And I suspect 2007 and whatever future year(s) this happens will be seen as the turning points.

If you're looking for ocean-driven signals as well, simply look at the trend of shoaling along the Atlantic-inflow stream and heat content storage coming from the Chukchi. They're pointing to the 2040s as well. Incidentally, this is around the same time aragonite undersaturation in the Arctic begins to show up, too (aragonite undersaturation starts in the 2030s around Antarctica). Full-on ecosystem disruption seems pretty ripe around that time.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on June 17, 2020, 02:06:19 AM
A one week look at the Bering Strait and Chukchi using band I4 shortwave.  The clouds and daily jump are a bit distracting, but one can see the warm Chukchi waters reading into the pack, as well as Bering inflows.
I reversed the colors to make it easier on the eyes.
Click to run.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 22, 2020, 11:31:10 AM
uni-hamburg amsr2-uhh, chukchi, may10-jun21.
forum still resizing gifs wider than 580px
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on June 22, 2020, 05:47:24 PM
Here is a PowerPoint ( large file ) on melt ponds, white ice , albedo , light scatter . Lots of pictures that we are missing this year . A nice primer on light and ice that helps make sense of the ITP WHOI data..

http://www.cgd.ucar.edu/events/20180409/files/h/Perovich_Wednesday.pdf

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 28, 2020, 03:43:05 PM
Nice.
mosaic pbuoy (https://data.meereisportal.de/gallery/index_new.php?active-tab1=method&buoytype=PB&region=all&buoystate=active&expedition=MOSAiC&buoynode=all&submit3=display&lang=en_US&active-tab2=buoy) movement over the yermak plateau. Large, to keep buoy separation, so maybe temporary.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on June 30, 2020, 11:26:53 PM
It occurred to me that sea ice age would highlight ice movement, particularly in the beaufort.
NSIDC, EASE-Grid Sea Ice Age, jan2000-jun2020, 7.3MB. Probably best viewed at half speed.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 02, 2020, 12:41:33 PM
A quick look at the latest simb386840 (https://www.cryosphereinnovation.com/386840) data in the beaufort appears to confirm recent air temps over 15C though that doesn't agree with the chart data from the website which may be surface temp. Assuming this is string data the ice looks in a cooler state than that in the mosaic area.
basic chart, few labels
1593644013 converts to Wednesday July 01, 2020 23:53:33 (pm) in time zone Europe/London (BST)


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 02, 2020, 08:11:13 PM
A bit of coding and we have more recent data from 386840. Just need  to convert the timestamp(EST) to readable date. Does anyone understand this format?
I take it back about the state of the ice. The temperature gradients look pretty much the same.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 02, 2020, 08:56:01 PM
Some recent data from simb 387850 (mosaic#3) (https://www.cryosphereinnovation.com/387850) while it is set up.
That looks a lot like a melt pond or cavity warming and cooling towards the end.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 03, 2020, 10:59:47 PM
Update on whoi itp buoys 104, 113, 114, 117 and 118 (https://www.whoi.edu/page.do?pid=163376) in the Beaufort with data at 6m depth.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 04, 2020, 10:42:20 PM
Had a look at whoi itp114 first, 7-250m depth, sep2019-jul2020
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 05, 2020, 02:07:34 AM
The temperature spike on ITP 114 microcat data looks like it almost hit zero at 6 meters although it has settled back to -1.24. The other buoy microcat or SamiCO2 stations on 104, 113, 114, 117, 118 temperature readings are from about -1.39 to -1.30 at 5-6 meters. Bottom melt everywhere in the Beaufort.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 06, 2020, 11:29:59 PM
closer to -0.9C
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 06, 2020, 11:50:54 PM
Uniquorn, The ITP buoys all show a similar spike then a drop. I have a theory as to why. Melt ponds form as insolation  peaks. Cracks form which allows surface fresh water to drain, decreasing salinity and reducing temperatures of surface waters below the ice.
Light penetration is reduced as white ice is the result of the surface water draining.
On the Sami data on ITP 118 the pCO2 sensor showed a rapid drop in pCO2. This may be due to
a phytoplankton bloom absorbing Dissolved CO2 from surface waters.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 07, 2020, 12:08:04 AM
You may be right about itp118 Bruce Steele, but there was a lot less cloud over itp114 during the days with the high peak. click to run
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 07, 2020, 03:24:43 AM
Uniquorn, The ITP buoys all show a similar spike then a drop. I have a theory as to why. Melt ponds form as insolation  peaks. Cracks form which allows surface fresh water to drain, decreasing salinity and reducing temperatures of surface waters below the ice.
Light penetration is reduced as white ice is the result of the surface water draining.
On the Sami data on ITP 118 the pCO2 sensor showed a rapid drop in pCO2. This may be due to
a phytoplankton bloom absorbing Dissolved CO2 from surface waters.
Shouldn't this be decreasing salinity and increasing temperatures of surface waters below the ice? The fresh water is near 0C while the water below is supposed to be at -1.8C.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 07, 2020, 05:03:09 AM
Oren, I was thinking the creation of white ice as surface ponds drained and the reduction of visible and UVR resulted in less heat to surface water below the ice via a reduction in insolation. Here is an excerpt from an article I posted month ago.

Stage I Prior to Melt Pond Onset on 15 June

Only 0.02 ± 0.01 of incoming PAR was transmitted through the snow-covered ice and spatial variability of light transmission did not change noticeably.

Stage II From 15 to 22 June

Once melt water became visible in large stretches at the ice surface, T¯(PAR)
increased by an order of magnitude to 0.31 on 22 June, while under-ice irradiance became increasingly variable.

Stage III From 23 June to 2 July

A short snowfall event followed by an enhanced surface melt resulted in discrete areas of white ice and melt pond, defining stage III. PAR transmittance and its spatial variability did not increase further during this stage. In fact, T¯(PAR)
 measured along the ND transect decreased from 0.23 to 0.16.

The observed large drop in T¯(PAR)
 measured along the ND transect on 28 June was attributed to the snowfall event. Unfortunately, surface albedo was not measured that day. Repeated measurements along this transects also showed more pronounced transmittance peaks beneath melt ponds while PAR transmittance below white ice became less variable over time (Supplementary Figure S3). These high transmittance values of discrete surface ponds became pronounced as outliers in the boxplots after the surface flooding in stage III. The larger areas of white ice transmitting less PAR compared to ponded ice also resulted in a skewed distribution and the median to be less than the calculated mean for most of the days within stage III. On the last sampling day, the variability in measured under-ice PAR levels decreased while T¯(PAR)
 remained unchanged at 0.20. As shown in the aerial drone image of the sampling area on 2 July (Figure 4E), more white ice had emerged at the surface due to ongoing drainage of melt ponds, leading to a drop in the melt pond coverage and a more uniform sea ice surface. It should be noted that the proposed stages of changes in T¯(PAR)
 are different from the stages of melt pond evolution described elsewhere (Eicken et al., 2002).

For the comparison of measured mean PAR transmittance and length-weighted average transmittance, T¯LW(PAR)
 was calculated for all D transects. To do so, T(PAR) values of 0.16 to 0.24 beneath white ice and 0.25 to 0.40 beneath ponded ice, measured along four destructive transects, were used. As shown in Figure 5B, T¯(PAR)
 and T¯LW(PAR)
 were not significantly different (t(12) = 0.005, p = 0.996) over the sampling period.

The increase in the transmission of one wavelength (305 nm) in the UVB spectrum and three wavelengths (325, 340, and 379 nm) in the UVA spectrum at 2 m is shown for all transects over the sampling period (Figure 5C). Beneath snow-covered sea ice in stage I, T¯(UVA)
, ranged from 0.01 to 0.02, while UVB radiation was not detectable. It is noted that surface and transmitted irradiance were integrated over the UVA wavelength spectrum (320–400 nm) prior to estimating T¯(UVA)
. With melt pond onset, T¯(UVA)
increased to 0.26 by the end of stage II on 22 June. Also, UVB radiation was detectable beneath the ice cover with a T¯(305nm)
 of 0.01. In stage III, transmission of UVA radiation did not increase further, displaying a mean of 0.21 ± 0.05 for D and ND transects. However, T¯(305nm)
 was on average greater during stage III than stage II, reaching a mean value of 0.07 ± 0.06. During stage III, UVR transmittance remained relatively consistent, while the variability in measured under-ice UVR levels decreased. Furthermore, UVR transmission through melt ponds was twice as high than through white ice. TWI(305nm) and TMP(305nm) ranged from 0.03 to 0.08 and 0.11 to 0.14, respectively

https://www.frontiersin.org/articles/10.3389/fmars.2020.00183/full
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 07, 2020, 05:20:35 AM
Good point, drainage increases albedo and reduces energy available below the ice. I was thinking of the direct temperature of the draining water.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 07, 2020, 05:54:20 AM
Oren, I have no idea if there has been a recent draining of melt ponds. I just remembered that draining melt ponds reduces light/ UVA in surface water. When I saw the 6 Meter temperature spikes at the ITP buoys it just seemed similar to the paper, timing seems similar also.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 07, 2020, 09:41:34 PM
beaufort temperatures at 6m depth, day 180-186
'quickly' thrown together
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: OffTheGrid on July 07, 2020, 10:51:35 PM
Drift charts for those buoys to show locations of these well above melting point temperatures under the ice.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: OffTheGrid on July 07, 2020, 11:05:27 PM
Seems good support for Hycoms prediction of rapid export of thickest ice from CAB along Beaufort and Chukchi Alaskan coast to soon be cut off by rapid meltout starting from centre out to coast of these seas.
Do we have any active sensor buoys in centre of these seas Uniquorn? [Edit: oops, answer is yes, missed 114 on your chart]
Click to play animation:
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 08, 2020, 10:51:58 AM
To clarify, post #624 shows temperatures at 6m depth. Temperatures just beneath the ice are not measured by these buoys.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 11, 2020, 10:09:58 PM
Rough check of Beaufort buoy drift timing with worldview, apr1-jul10 4.6MB
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 11, 2020, 11:22:04 PM
whoi itp buoy drift speed, iabp data, mar30-jul11
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on July 12, 2020, 08:34:52 AM
Imagine that valuable data lost in 116. I'm so sad right now.  :(
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Pagophilus on July 12, 2020, 05:50:37 PM
Rough check of Beaufort buoy drift timing with worldview, apr1-jul10 4.6MB
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 12, 2020, 11:34:35 PM
Rough check of Beaufort buoy drift timing with worldview, apr1-jul10 4.6MB
rough check of Pagophilus doing a rough check
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 14, 2020, 10:29:24 PM
If macid is around I'd really like to see an update of this (https://forum.arctic-sea-ice.net/index.php/topic,2417.msg230077.html#msg230077)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 14, 2020, 11:12:58 PM
Timmermans 2018 (https://clima.caltech.edu/files/2018/11/Timmermans.pdf): Fate of the Halocline Heat and arctic ocean stratification
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 17, 2020, 12:51:46 AM
Comparison of bands I2 and I4. Attempting to highlight the highest ssts in relation to the ice.

First attachment, Nares entrance in lower right.

Second is part of the chukchi, note the ssts are cooler than the ice in the upper left.  The warm plume is attacking the ice edge in the center.

Both need a click.  Contrast boosted.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 17, 2020, 04:54:56 AM
Interesting eddies along 75°N in the northern ESS.  What are the chances the shelf break is there?
Click it.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 17, 2020, 10:34:43 AM
Interesting you chose Lincoln sea. I've been wondering if the open water north of CAA Greenland is evidence of coastal upwelling. The ice doesn't lift off north of PGAS.

High contrast noaa bathy map to highlight shallow water depth.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 17, 2020, 11:12:51 AM
I think the ice is bouncing and sliding off PGAS because of the general direction of movement of the pack and because of the "inner elbow" where the ice must make a right turn. If this movement keeps up, there will be a lift off from PGAS as well.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 17, 2020, 11:22:04 AM
I was hoping for another cloud free day in the Lincoln to have two days, but isn't happening.  Just happy to have the full suite of RAMMB imagery updating.
 Here's Lincoln see with heavy contrast.  I see two possible areas of upwelling.  Normally, I'm used to cooler water being upwelled, as that's what happens outside of the arctic.  One is in the upper left, the other is near the mouth of the first fjord up from the Nares entrance.  I also see a slight daily rhythm in the opening, I'm attributing to the sun. 
Needs a click
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 17, 2020, 01:26:51 PM
I think this area might tell us something
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 17, 2020, 05:30:27 PM
Not really bouncing. Two points of interest here, the large lift off and the smaller floe (marked) drifting in a different direction

added large rammb, jul13-17
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 18, 2020, 10:59:21 AM
Thanks, very interesting.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on July 18, 2020, 03:47:37 PM
IF there's any merit in the idea that the lift off is caused by internal waves reflected back from Laptev then as they move towards Greenland/Ellesmere they, at an atomic level, should acquire rotational energy as they move away from the pole/axis, thus where the coastline opens up that energy should penetrate deep into, for instance, the PGAS before emerging as turbulence/melt or simply added inertia through the channels. I'm thinking the rotation is acw/ccw and when it hits the coast the energy accelerates into the point of contact, and here cross hatching occurs and it's these raised features which move the ice from the coast, coupled with enhanced 'ice shelf' erosion. The initial wave motion may be spent in the upwelling but the rotational fraction will continue to build as the front moves south towards Banks Is.. I wonder too if the wave seperates as indicated by the bathymetry, and whether the movement of the fast ice, and the previously grounded 'foot' of the Splaltegletscher, north of 79N are a consequence? if so then Atl. penetration is going to ramp up change rather quickly.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 18, 2020, 04:51:56 PM
John, why assume internal waves as the reason, if the sustained anti-cyclone wind provides a good enough and quite obvious explanation?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 18, 2020, 08:52:10 PM
If the explanation is obvious, why no lift off from pgas? And no bounce, which probably wasn't obvious. edit: maybe ossifrage has an explanation.

Posting a rough amsr2 overlaid onto mercator (model) 34m salinity while I attempt to work through some suggested presentation improvements. jun1-jul17
scales are probably meaningless with the overlay. red salinity>yellow>green>blue

Laptev modelled diluting or mixing the salty atlantic finger.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 18, 2020, 09:28:40 PM
Toggling between the last available frame from I4 and I2 bands. Trying to show, what I suspect is, Lena discharge extending into the Laptev.
Needs click
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 18, 2020, 09:55:11 PM
If the explanation is obvious, why no lift off from pgas? And no bounce, which probably wasn't obvious. edit: maybe ossifrage has an explanation.

Posting a rough amsr2 overlaid onto mercator (model) 34m salinity while I attempt to work through some suggested presentation improvements. jun1-jul17
scales are probably eaningless with the overlay. red salinity>yellow>green>blue

Laptev modelled diluting or mixing the salty atlantic finger.
Uniquorn, I don't mean the explanation is "obvious obvious", just that the lift off in general was due to the anti-cyclonic winds according to my understanding. Why no lift-off from PGAS I do not know, but internal waves reflected from Laptev (as John proposed) sounds like a rather far-fetched explanation to my layman ears. Admittedly my knowledge is severely limited, so I'll try to keep an open mind and learn from my betters here.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 18, 2020, 11:11:15 PM
Admittedly my knowledge is severely limited, so I'll try to keep an open mind and learn from my betters here.
Me too
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 18, 2020, 11:14:51 PM
Toggling between the last available frame from I4 and I2 bands. Trying to show, what I suspect is, Lena discharge extending into the Laptev.
Needs click
To verify that I think you need to go back further and show the flow. Otherwise I think it is probably insolation on open water. Separated stills might be enough.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on July 18, 2020, 11:20:47 PM
So what are we actually seeing in these shots? The water temperature or sediments?

Because if it's the sediments, we can assume river discharge.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 19, 2020, 12:49:05 AM
Got every image available in the archive, slim pickings at times. It's unfortunate there is no imagery except day night updating today, clear skies help. Anyhow, I sped it up to help see through the clouds.  Perhaps I'm biased, but I see a plume extending out, but certainly curious as others interpretation. Incidentally, you can see the enhanced cloud/fog formation off the warmest SSTs.
Click, kinda big
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 19, 2020, 12:51:19 AM
So what are we actually seeing in these shots? The water temperature or sediments?

Because if it's the sediments, we can assume river discharge.
It is shortwave IR, it's temperature, I've used it with GOES imagery as well.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on July 19, 2020, 08:40:04 AM
Jay, do you know, which band would be capable of showing the sediments?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 19, 2020, 10:11:47 AM
Jay, do you know, which band would be capable of showing the sediments?
Geocolor would likely be best, but a far as individual bands, I've seen high resolution band I1 "red" pick it up (M5 "red" also), and band M4 "green".  Sediment is normally brown, a color combination of red and green, so I'd use one of those.  The green band could also pick up algae as well I'd think.  When toggling though the bands, I'd say green does best.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on July 19, 2020, 10:19:58 AM
Thanks a lot, Jay!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 19, 2020, 11:26:05 AM
Salinity at 34m, jul18 2018-2020
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 23, 2020, 01:22:37 AM
I was making a gif of the Yermak plateau area, but noticed some other interesting motions, hence the wider shot. Hopefully we get another clear day and updating RAMMB...
Click it.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 23, 2020, 01:30:58 AM
That is great. Doesn't look like Isn't wind.
Anything further up? FJL?
https://col.st/imkHC (while it is in the archive)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on July 23, 2020, 11:51:46 AM
I'm guessing the low north of FJL enhanced incoming which would cause movement along the slope, the actual water more likely to head for Nares. The tides are still large at Bear Is. (https://www.tideschart.com/Svalbard-and-Jan-Mayen/Svalbard/Bjornoya/Bear-Island-Barents-Sea/Weekly/)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 25, 2020, 05:51:38 AM
Band I4, opening north of Ellesmere Island. Heavy contrast.
87 ish hour loop.
Click to run.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 25, 2020, 11:31:43 AM
Nice, though I'm not sure what band I4 is showing. Mercator temperature resolution is too low to show much change on the Ellesmere coast yet. Salinity is often a better indicator of up/downwelling. Here is the modelled 0m salinity jul1-24 and 0m temperature, jul18-24

It could just be insolation, probably both.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 25, 2020, 12:06:45 PM
Nice, though I'm not sure what band I4 is showing. Mercator temperature resolution is too low to show much change on the Ellesmere coast yet. Salinity is often a better indicator of up/downwelling. Here is the modelled 0m salinity jul1-24 and 0m temperature, jul18-24

It could just be insolation, probably both.
It's sensitive to temperatures.  I was thinking insolation was playing a role as well.  The eddies are interesting.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on July 26, 2020, 11:57:14 AM
Svalbard on the bottom. I flipped to put north upwards. Band I4 to show the SSTs. Overlayed with snowmelt RGB (blue) to show the ice edge.
Contrast boosted.
Needs click
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 28, 2020, 12:02:20 AM
Good clear view north of CAA Greenland. Some contrast adjustments.
Signs of rotation in the middle just north of Lincoln
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on July 28, 2020, 04:23:31 PM
It's not just some of the thickest ice that will go south through the "garlic press" into oblivion. Some of the fresh water layer at 30m depth is headed for the "garlic press" too.  That 30m salinity animation has a lot of different things going on.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 28, 2020, 08:50:52 PM
mercator salinity, 34m, mar21-jul27
best viewed at half speed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: ArcticMelt2 on July 29, 2020, 03:46:22 PM
By the way, the storm in Barrow did not weaken much, as before, waves of more than 2 meters in height are observed.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: ArcticMelt2 on July 29, 2020, 08:15:07 PM
The waves at Barrow have really intensified. Aren't the models cheating about easing the storm?  :P
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 29, 2020, 11:01:26 PM
beaufort/chukchi low for reference
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Freegrass on July 30, 2020, 08:28:25 AM
Isn't that water in the Beaufort and the CAB a little too salty?  :-\
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: tobiasR on July 30, 2020, 12:40:09 PM
Two active ITP buoys 113 & 114 in the Beaufort sea are worth watching during the storm, both showing a massive mixing event in the form of a decreasing salinity gradient, down to a few hundred meters below sea level. It's destroying the freshwater lens while temps in the upper layers have been increasing. I expect rapid melt out of what's left in Beaufort and Chuckci seas in the coming days.


Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 30, 2020, 03:18:04 PM
Too salty? - Don't know. I find it difficult to interpret 0m salinity under ice and after seeing the Tbuoy data I'm not sure that much should be inferred from modelled data. That said, itp114 looks interesting recently, though data starts at 7m depth. Will check it out later.
image removed
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on July 30, 2020, 03:21:13 PM
As it happens, a new user just posted about the same buoys, see above.
Welcome, tobiasR.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: glennbuck on July 30, 2020, 03:28:40 PM
DMI, but might not be accurate.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 30, 2020, 03:42:45 PM
As it happens, a new user just posted about the same buoys, see above.
Welcome, tobiasR.
Welcome indeed!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 30, 2020, 04:14:11 PM
Perhaps a separate thread for the utqiagvik webcam would be appropriate.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on July 30, 2020, 04:31:24 PM
tobiasR, If you look at today’s update you can see that the ITP 113 contours has settled down to a more normal profile today. The large upward and downward spike of 31 salinity (halocline) water has changed into a smaller spike that more accurately describes conditions. I think when buoys move too fast the cables that the profiler rides on bang around and send false signals. Today both halocline heat and salinity look to have shoaled another ten meters so that the top of the halocline is about at 25 meters . The other thing you can do is look at the microcat data to help verify what the contours are showing. So although the 113 temp/ salinity contours you posted showed 31 salinity to the surface the microcat at 6 meters shows 26.6 salinity. I would trust the detail of the two microcat sensors over the more broad brush numbers that the temp/salinity contours show especially when there is a weird spike in contours.
 With that all said I think the shoaling of the halocline to twenty five meters is a large jump. More to come as things melt out I believe.
 And welcome aboard !

Normal anticyclonic conditions tend to pull fresh water from ice melt and rivers into the center of the gyre while cyclonic conditions allow some of the accumulated fresh water to flow laterally away from the center. As the surface fresh water moves away from the gyres center the warmer saltier halocline can shoal to a shallower depth. When anticyclonic conditions return the shoaling reverses and the halocline gets shoved deeper while the surface fresh water layer thickens. 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: ArcticMelt2 on July 30, 2020, 04:35:23 PM
Perhaps a separate thread for the utqiagvik webcam would be appropriate.

I do not think. There are now many reports of this just because there was a rare powerful storm. Then interest in such observations will quickly subside.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: blumenkraft on July 30, 2020, 04:39:05 PM
Perhaps a separate thread for the utqiagvik webcam would be appropriate.

Your wish is my command, Uniquorn.

It's here >> https://forum.arctic-sea-ice.net/index.php?topic=3226.new#new
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: aslan on July 30, 2020, 04:40:10 PM
It can be noted also that there is a surge event ongoing for the northern coast of Alaska. I don't have knowledge of a station measuring waves height for Arctic coast of Alaska, but at least there is a surge of about 0.5 meters since the 27th of July at Prudhoe. Waves will pill up above, and as sea level is already high, tops of waves reach even higher level. As a side note, waters levels at Prudhoe are higher than in 2012. In 2019 waters levels were even higher than, now, but were not as long lasting.

https://tidesandcurrents.noaa.gov/waterlevels.html?id=9497645&units=metric&bdate=20200725&edate=20200801&timezone=GMT&datum=MLLW&interval=6&action=
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: aslan on July 30, 2020, 05:28:53 PM
For ITP 113 and 114 there is also the question of temperature. The cold pool at the surface was definitively mixed, as temperature surged at surface.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: prokaryotes on July 30, 2020, 06:06:09 PM
It can be noted also that there is a surge event ongoing for the northern coast of Alaska. .. at least there is a surge of about 0.5 meters since the 27th of July at Prudhoe. Waves will pill up above, and as sea level is already high, tops of waves reach even higher level. As a side note, waters levels at Prudhoe are higher than in 2012. In 2019 waters levels were even higher than, now, but were not as long lasting.
Notice that the region just about 100 km farther westerly is a known hot spot for coastal erosion, consisting of permafrost soils - see below footage of Drew Point coastline damage...

https://youtu.be/b27eXPialt4?t=472
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 30, 2020, 07:24:05 PM
7m temperatures have been slowly rising since ~day170 (jun18). I think that is due to insolation.
During recent days the profiler has often been unable to rise above 250m, probably due to high drift speed. I don't know the reason for the recent drop in temperature at 5m, mixing down to 25m?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 30, 2020, 08:15:56 PM
whoi itp114 7-250m, a bit longer due to interesting profile change on day136.  Also a short ani of recent salinity down to 800m to show profiler struggling.
Thicker lines, bigger titles on these :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: tobiasR on July 30, 2020, 08:33:01 PM
Thanks uniquorn & Bruce for the correction, I got a little over excited there :) I looked at the data files and there's indeed missing profiles last few days for 5-200m depth so it's just filling in colours.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on July 30, 2020, 10:53:06 PM
Good clear view north of CAA Greenland. Some contrast adjustments.
Signs of rotation in the middle just north of Lincoln
Following up on rotation north of Lincoln Sea
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 03, 2020, 11:20:51 PM
update on rotation north of Lincoln. Here using worldview aqua and terra interleaved, jul21-aug3.
slight contrast enhancement.

Also posting some surface net downward shortwave flux differences for reference, 202006 minus 201206 to 201906. Note that the scale is -100to100
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 05, 2020, 01:12:33 PM
Deep Flow Variability Offshore South-West Svalbard (Fram Strait) (https://www.mdpi.com/2073-4441/11/4/683)
Quote
Abstract:
Water mass generation and mixing in the eastern Fram Strait are strongly influenced by the interaction between Atlantic and Arctic waters and by the local atmospheric forcing, which produce dense water that substantially contributes to maintaining the global thermohaline circulation.
The West Spitsbergen margin is an ideal area to study such processes. Hence, in order to investigate the deep flow variability on short-term, seasonal, and multiannual timescales, two moorings were deployed at ~1040 m depth on the southwest Spitsbergen continental slope. We present and discuss time series data collected between June 2014 and June 2016. They reveal thermohaline and current fluctuations that were largest from October to April, when the deep layer, typically occupied by Norwegian Sea Deep Water, was perturbed by sporadic intrusions of warmer, saltier, and less dense water. Surprisingly, the observed anomalies occurred quasi-simultaneously at both sites, despite their distance (~170 km).
We argue that these anomalies may arise mainly by the effect of topographically trapped waves excited and modulated by atmospheric forcing. Propagation of internal waves causes a change in the vertical distribution of the Atlantic water, which can reach deep layers. During such events, strong currents typically precede thermohaline variations without significant changes in turbidity. However, turbidity increases during April–June in concomitance with enhanced downslope currents. Since prolonged injections of warm water within the deep layer could lead to a progressive reduction of the density of the abyssal water moving toward the Arctic Ocean, understanding the interplay between shelf, slope, and deep waters along the west Spitsbergen margin could be crucial for making projections on future changes in the global thermohaline circulation

Introduction
Water masses in the eastern Fram Strait, strongly influenced by the interaction between Atlantic
and Arctic waters and by local atmospheric forcing, substantially contribute to drive the global
thermohaline circulation [1–4]. There is a remarkable variability in the system due to several
forcing mechanisms (e.g., atmospheric, internal, tidal, shelf dynamics) that play an important role,
especially in the upper layer [5–10]. On the contrary, it is not completely clear which processes are responsible for the inter-annual and seasonal deep flow variability in the western offshore Spitsbergen region
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 05, 2020, 02:57:46 PM
mercator(model) current at 34m depth, mar21-aug4
best viewed at half speed ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 06, 2020, 12:02:53 AM
Delaunay triangulation of a selection of iabp buoys (http://iabp.apl.washington.edu/maps_daily_table.html) day90-218, ~2days/sec
will probably replace with a smaller version
Will have to check that dropout, Octave delaunay not happy with 3 buoys in a row perhaps.
Possible eddies in the Beaufort. Best viewed at 2x speed.
Only a couple of the buoys are mosaic.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 08, 2020, 11:05:58 AM
nice image from earth observatory of the arctic low from jul28 for reference. Full size image here (https://earthobservatory.nasa.gov/images/147070/arctic-lows)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on August 08, 2020, 04:07:08 PM
Yermak plateau area.  Contrast increased. Needs a click.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 08, 2020, 06:55:57 PM
Thanks JayW. Been wanting that for ages :)
Even more active than I imagined. 280km from nearest land. I think that's 82.5N which puts the eddy near the white blob.  https://col.st/5Us0O (available for a while)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 08, 2020, 08:27:07 PM
I remember you found this last year
82.5N is the northern edge of the Yermak plateau and the waves appear rotational above the plateau, spreading north over deeper water. Based on repeated views of lower concentration ice over this area on amsr2 there is a lot of mixing in this area. That looks like upwelling on a grand scale.
Mosaic buoys showed cyclic movement over this area suggesting a tidal influence.
The evidence is becoming overwhelming.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on August 08, 2020, 09:52:04 PM
I think it's rotation says it's heading south so my guess was here, be nice to know for sure.
Thanks  :)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 09, 2020, 09:18:01 PM
20200807 eddy centre starts at around 82.5N 9E, moves a little north and to ~13E
81.3N is close to the ice edge.
Worldview shows it at around 82.57N 5.26E on aug7 https://go.nasa.gov/2XLHTCF
That's a trip along 2/3 of the plateau northern edge (https://maps.ngdc.noaa.gov/viewers/bathymetry/) 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: JayW on August 09, 2020, 10:54:43 PM
Thanks JayW. Been wanting that for ages :)
Even more active than I imagined. 280km from nearest land. I think that's 82.5N which puts the eddy near the white blob.  https://col.st/5Us0O (available for a while)
I agree, seems more expansive than what we saw last year.  Wonder if it's due to ice thickness, perhaps due to the higher tide cycle,  interesting for sure.   I see it starting at roughly 7°E.  I see a separate feature at 81.3°N at the ice edge that I don't see is directly related.

Sverdrup channel using I4 with snow RGB for ice.  Relatively warm water being input from the fjords.
Contrast and brightness boosted. Click to run.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 09, 2020, 11:20:20 PM
Thanks. A good reason for the quick melt. Also coming from the north by the looks of it. Maybe from Nansen Sound, though I thought the current there was supposed to be south.

Bookmarking A-Teams (https://forum.arctic-sea-ice.net/index.php/topic,3017.msg280330.html#msg280330) post for ref
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 11, 2020, 09:50:12 PM
mercator 0m temperature(SST) with amsr2-uhh overlay, jun1-aug10
used 'lighten only' in gimp for a test. Labels are much better
Best viewed at half speed.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on August 12, 2020, 12:08:17 AM
Looking at Mercator (http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20200801/20200806/2/2) salinity 30m it seems the Atl. waters are short circuiting and returning along Lomonosov from Laptev, they appear to be mixing with returns from ESS creating turbulence immediately beneath the openings in the ice north of Greenland.  I also suspect overflow from the Canadian side, by Belov trough, is forcing internal waves and actual movement in the basal layers towards Fram.
Strange that it [Atl.] doesn't get mixed maybe there's a wall of inert water holding station along the American side?
 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 17, 2020, 03:32:03 PM
mercator current 92m, mar21-aug17

mercator salinity and current for this day from 2017-2020 or nearest where available (salinity useful for showing up/downwelling)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: vox_mundi on August 21, 2020, 11:47:13 PM
Arctic Ocean Moorings Shed Light On Winter Sea Ice Loss
https://phys.org/news/2020-08-arctic-ocean-winter-sea-ice.html

The eastern Arctic Ocean's winter ice grew less than half as much as normal during the past decade, due to the growing influence of heat from the ocean's interior, researchers have found.

(https://ams.silverchair-cdn.com/ams/content_public/journal/jcli/33/18/10.1175_jcli-d-19-0976.1/2/m_jclid190976-f1.png?Expires=1600968408&Signature=GgNWbk1ime08BMyVq7H6tDvmFWI3uzMR4HHWDeQWdELs-7oabClO-7QT2LxKfKzCLsrVWDNNciUrhwrbSzX175UvgwWRmvgvmU3WjGb8JMcwTZe9LFIlAf2CmieyxxIkTyf7ObX1BY7K~oQXPAKmlNfJXZG9sia9PJocbKFCR3jH0XzboZs6SwfPg2lw4fKOQxTEycpjp8QeYIPBRgKshhze4iUkKwwgUutAzzqN7mC818XMkZt00Nuyr7mJwHRUnuIfApgmHXJ~t5YMGwxBANj2DjTteAnKQX4VwhQRb0CyZH~6MIlnCe~teturCrHe8ipo~XoG8mvmw2USG8Vm7A__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)

The finding came from an international study led by the University of Alaska Fairbanks and Finnish Meteorological Institute. The study, published in the Journal of Climate, used data collected by ocean moorings in the Eurasian Basin of the Arctic Ocean from 2003-2018.

The moorings measured the heat released from the ocean interior to the upper ocean and sea ice during winter. In 2016-2018, the estimated heat flux was about 10 watts per square meter, which is enough to prevent 80-90 centimeters (almost 3 feet) of sea ice from forming each year. Previous heat flux measurements were about half of that much.

"In the past, when weighing the contribution of atmosphere and ocean to melting sea ice in the Eurasian Basin, the atmosphere led," said Igor Polyakov, an oceanographer at UAF's International Arctic Research Center and FMI. "Now for the first time, ocean leads. That's a big change."

Typically, across much of the Arctic a thick layer of cold fresher water, known as a halocline, isolates the heat associated with the intruding Atlantic water from the sea surface and from sea ice.

This new study shows that an abnormal influx of salty warm water from the Atlantic Ocean is weakening and thinning the halocline, allowing more mixing. According to the new study, warm water of Atlantic origin is now moving much closer to the surface.

"The normal position of the upper boundary of this water in this region was about 150 meters. Now this water is at 80 meters,"
explained Polyakov.

(https://ams.silverchair-cdn.com/ams/content_public/journal/jcli/33/18/10.1175_jcli-d-19-0976.1/2/m_jclid190976-f11.png?Expires=1600968408&Signature=21S10hkjToB~nBXpzmaaxhc3obKVxLm-2wZKUtilKN5qDvvqplSYH6wHrrqVLTbwQ3u8iI49b6B8AV-fDVhcwWkN4l6g-jlT-tKJBGjdHHlmH4aWciUlWt1nJDZKvygFDaeMzXXt~eoPsjfrY34ZagknWLljHNJtxjmLEu-TAl7f~g3UpMXDLr~Lm4If9ihhs8RX57Mtc8n2LMfX0wpb4EBeipU9jRUnNWfD7Uyyhl7atsrMJumSw7zQf7mfn1KwB2IcbK~IZyNbIVd5oDBJ-o1HFbuZxiVA8p1kL1JaQWUw5VK87f4h8O0qOJgwGEc07Ibz5DEvDJ0w9ltK34ve-Q__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)

A natural winter process increases this mixing. As sea water freezes, the salt is expelled from ice into the water. This brine-enriched water is heavier and sinks. In the absence of a strong halocline, the cold salty water mixes much more efficiently with the shallower, warm Atlantic water. This heat is then transferred upward to the bottom of sea ice, limiting the amount of ice that can form during winter.

Polyakov and his team hypothesize that the ocean's ability to control winter ice growth creates feedback that speeds overall sea ice loss in the Arctic. In this feedback, both declining sea ice and the weakening halocline barrier cause the ocean's interior to release heat to the surface, resulting in further sea ice loss. The mechanism augments the well-known ice-albedo feedback—which occurs when the atmosphere melts sea ice, causing open water, which in turn absorbs more heat, melting more sea ice.

When these two feedback mechanisms combine, they accelerate sea ice decline. The ocean heat feedback limits sea ice growth in winter, while the ice-albedo feedback more easily melts the thinner ice in summer.

"As they start working together, the coupling between the atmosphere, ice and ocean becomes very strong, much stronger than it was before," said Polyakov. "Together they can maintain a very fast rate of ice melt in the Arctic."

Polyakov and Rippeth collaborated on a second, associated study showing how this new coupling between the ocean, ice and atmosphere is responsible for stronger currents in the eastern Arctic Ocean.

According to that research, between 2004-2018 the currents in the upper 164 feet of the ocean doubled in strength. Loss of sea ice, making surface waters more susceptible to the effects of wind, appears to be one of the factors contributing to the increase.

The stronger currents create more turbulence, which increases the amount of mixing, known as shear, that occurs between surface waters and the deeper ocean. As described earlier, ocean mixing contributes to a feedback mechanism that further accelerates sea ice decline.

(https://agupubs.onlinelibrary.wiley.com/cms/asset/0023930a-70dd-48e2-9fd3-330ee68489c5/grl61024-fig-0002-m.png)

Igor V. Polyakov et al, Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean, Journal of Climate (2020)
https://journals.ametsoc.org/jcli/article/33/18/8107/353233/Weakening-of-Cold-Halocline-Layer-Exposes-Sea-Ice

Igor V. Polyakov et al. Intensification of Near‐Surface Currents and Shear in the Eastern Arctic Ocean, Geophysical Research Letters (2020).
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL089469
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: johnm33 on August 22, 2020, 12:24:43 PM
I was looking at movement along the CAA coast, there was an interesting feature further out so I wondered what caused it and fitted it to the bathymetry.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 23, 2020, 07:51:52 PM
Igor V. Polyakov et al, Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean, Journal of Climate (2020)
https://journals.ametsoc.org/jcli/article/33/18/8107/353233/Weakening-of-Cold-Halocline-Layer-Exposes-Sea-Ice
Thanks vox.

Quote
Heat associated with oceanic currents originating from lower latitudes provides an important, and year-round, source of heat to the Arctic Ocean (e.g., Carmack et al. 2015). The dominant external source of oceanic heat is the warm (temperature > 0°C) and salty water of Atlantic origin [Atlantic Water (AW)], which is distributed throughout the deep basins at intermediate depths (~150–900 m; Fig. 1) and holds sufficient heat to melt the Arctic sea ice 3–4 times over (Carmack et al. 2015). Across much of the eastern (>70°E) Eurasian Basin (EB) this heat is isolated from the surface, and hence the sea ice, by large vertical density gradients associated with the Arctic halocline (60–150 m; Fig. 1). The presence of the halocline impedes the transport of AW heat upward toward the surface across much of the Arctic Ocean (e.g., Fer 2009). The exception to this is the western (<70°E) Nansen Basin where substantial turbulent mixing linked to the tides (Fer et al. 2010; Padman and Dillon 1991; Rippeth et al. 2015; Renner et al. 2018) and wind events (e.g., Provost et al. 2017; Graham et al. 2019) supports heat fluxes in excess of 50 W m−2.
edit: my bold

Maybe has something to do with this
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 23, 2020, 09:59:24 PM
Position of moorings and potential temperature chart 2013-2017 for the paper above.
Quote
Depth–time diagram of potential temperature θ (°C) from the M13 mooring. Black lines show the depth of the halocline base and lower Atlantic Water boundary, both defined by 0°C isotherms.
https://en.wikipedia.org/wiki/Potential_temperature
Quote
The potential temperature of a parcel of fluid at pressure P is the temperature that the parcel would attain if adiabatically brought to a standard reference pressure P 0, usually 1,000 hPa (1,000 mb).

Now, how long does it take for laptev water to reach the yermak plateau/north of Greenland?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 24, 2020, 06:50:09 AM
The paper vox linked to is indeed very interesting. I missed the highligted (by you, Uniqorn?) mention of tides. And it makes me wonder - if there is "substantial" turbulent mixing due to tides and wind in the Nansen Basin west of Franz Josef Land, where are the visible effects of this?

And what is meant by "substantial" - and how come that you highlighted parts of the sentence without saying so, and forgot the latter half of the sentence, i.e. the wind mention? Saying "in excess of" 50 W/m2 is not really good enough, is this a continuous heat flux or something that happens occasionally? As in "substantial" once a month for three hours?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2020, 11:42:39 AM
If it makes you wonder binntho, we must be getting somewhere. I've edited the post to show my bold and I'm pleased that it made you notice it. There's no need to be suspicious. I'm just looking for evidence to support my ideas, as you should do.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 24, 2020, 01:59:30 PM
If it makes you wonder binntho, we must be getting somewhere. I've edited the post to show my bold and I'm pleased that it made you notice it. There's no need to be suspicious. I'm just looking for evidence to support my ideas, as you should do.
It does make me wonder - it seems dishonest to make changes in other people's text without making it clear that you are doing so. And it seems dishonest to seperate the two halves of the sentence, to make it look as if it is only about tides.

In fact, the article does not count as evidence of any substantial tidal effect, and here I mean substantial as in making a discernible difference to the overall state of the ice.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2020, 03:22:49 PM
So we disagree again. It's quite common on this forum to bold parts of text to highlight them.
I'll give you the chance to retract the slur on my integrity before reporting you to the moderator.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 24, 2020, 03:43:55 PM
So we disagree again. It's quite common on this forum to bold parts of text to highlight them.
I'll give you the chance to retract the slur on my integrity before reporting you to the moderator.
Please report me. It is dishonest if you don't mention it, if you do mention it it is perfectly normal. In the first post I asked if you had done it and you answered snidely, so you are obviously not aware that this is not how things are done.

Whether or not is dishonest to only highligt only part of the sentence, I'll happily retract that, it could have been a simple error.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2020, 06:20:25 PM
I've edited the post to include the whole sentence.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2020, 06:50:39 PM
A longer look at the low concentration north of the yermak plateau, western end of the Nansen basin. Note how the low concentration stays in the same area despite ice drifting over it. In my view this low concentration can't be due to wind and there is good evidence of turbulence, possibly caused by tides
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2020, 06:53:06 PM
Also reposting some stuff from west of FJL in january (https://forum.arctic-sea-ice.net/index.php/topic,2417.msg246279.html#msg246279) (already on this thread)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2020, 06:54:18 PM
buoys over the yermak plateau

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2906.0;attach=262794;image)

a wider view of more buoys

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2906.0;attach=271292;image)

evidence of turbulence. Thanks to JayW

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=3030.0;attach=280107;image)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 24, 2020, 07:16:24 PM
Today's worldview terra of the yermak plateau area. Too cloudy again for rammb I think.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 26, 2020, 03:43:52 PM
Tidal forcing, energetics, and mixing near the Yermak Plateau (http://bora.uib.no/handle/1956/10818)
I.Fer1,3, M. Müller2, and A. K. Peterson1,
Published: 27 March 2015
Quote
Abstract
The Yermak Plateau (YP), located northwest of Svalbard in Fram Strait, is the final passage for the inflow of warm Atlantic Water into the Arctic Ocean. The region is characterized by the largest barotropic tidal velocities in the Arctic Ocean. Internal response to the tidal flow over this topographic feature locally contributes to mixing that removes heat from the Atlantic Water. Here, we investigate the tidal forcing, barotropic-to-baroclinic energy conversion rates, and dissipation rates in the region using observations of oceanic currents, hydrography, and microstructure collected on the southern flanks of the plateau in summer 2007, together with results from a global high-resolution ocean circulation and tide model simulation. The energetics (depth-integrated conversion rates, baroclinic energy fluxes and dissipation rates) show large spatial variability over the plateau and are dominated by the luni-solar diurnal (K1) and the principal lunar semidiurnal (M2) constituents. The volume-integrated conversion rate over the region enclosing the topographic feature is approximately 1 GW and accounts for about 50% of the M2 and approximately all of the K1 conversion in a larger domain covering the entire Fram Strait extended to the North Pole. Despite the substantial energy conversion, internal tides are trapped along the topography, implying large local dissipation rates. An approximate local conversion–dissipation balance is found over shallows and also in the deep part of the sloping flanks. The baroclinic energy radiated away from the upper slope is dissipated over the deeper isobaths. From the microstructure observations, we inferred lower and upper bounds on the total dissipation rate of about 0.5 and 1.1 GW, respectively, where about 0.4–0.6 GW can be attributed to the contribution of hot spots of energetic turbulence. The domain-integrated dissipation from the model is close to the upper bound of the observed dissipation, and implies that almost the entire dissipation in the region can be attributed to the dissipation of baroclinic tidal energy.
My bold

It's possible that this contributes to the lower concentration ice in this area very recently.
A short extract that may also be relevant.
Quote
Baroclinic  disturbances in response to tidal flow over topography above the critical latitude are thus topographically trapped near the generation site (a continental slope, a ridge, or a seamount). The energy propagation of topographically trapped waves is possible  along  the  slope,  around  the  topographic  feature  with negligible radiation away in the cross-slope direction. This is analogous to the sub-inertial baroclinic trapped waves propagating  around  isolated  seamounts  (Brink,  1989).  Trapped tides  dissipate  their  energy  locally,  or  elsewhere  along  the topography, leading to substantial vertical mixing
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 26, 2020, 05:11:21 PM
It's possible that this contributes to the lower concentration ice in this area very recently.

Entirely possible. Although I must admit that I find it difficult to get a grip on the scale and understand the energy involved.

For example, what is meant by

Quote from: http://bora.uib.no/handle/1956/10818
From the microstructure observations, we inferred lower and upper bounds on the total dissipation rate of about 0.5 and 1.1 GW, respectively, where about 0.4–0.6 GW can be attributed to the contribution of hot spots of energetic turbulence. The domain-integrated dissipation from the model is close to the upper bound of the observed dissipation, and implies that almost the entire dissipation in the region can be attributed to the dissipation of baroclinic tidal energy.

They express something called "dissipation rate" in the region of 1GW - is this a measure of water flow or heat flow? I suspect the former, since they attribute it to "tidal energy", which is definitely not heat.

And if this is a measure of water flow then we should be able to compare it to a terrestrial hydropower station. Just down the road from me they are building a massive dam (the Grand Reneissance Dam or GERD) with a max planned installed capacity of 6.45GW from the flow of the Blue Nile, from an average flow of some 1500 m3/second which equates to 0.0015 Sverdrup.

Compare this with the West Spitzbergen Current which flows in over the Yearmak Plateau, it is not easy to find exact numbers but according to Wikipedia it swings between 5 and 20 sverdrups,

So my conclusion from this, given that I am not totally misunderstanding the 1GW in the article, is that the tidal effect over the Yearmak Plateau is smaller than the West Spitzbergen Current by a factor of  at least 10.000.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 26, 2020, 08:13:36 PM
Turbulence dissipation is the rate at which turbulence kinetic energy is converted into thermal internal energy.

Quote
What is Turbulence Energy Dissipation Rate? (https://www.calculator.org/properties/turbulence_energy_dissipation_rate.html)
The dissipation of the kinetic energy of turbulence(the energy associated with turbulent eddies in a fluid flow) is the rate at which the turbulence energy is absorbed by breaking the eddies down into smaller and smaller eddies until it is ultimately converted into heat by viscous forces.

But this is more likely to be the larger contributor
Quote
Trapped tides  dissipate  their  energy  locally,  or  elsewhere  along  the topography, leading to substantial vertical mixing
My bold
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 26, 2020, 08:59:38 PM
Some background reading on trapped diurnal internal tides (https://ui.adsabs.harvard.edu/abs/2015DSRII.112...61J/abstract) from studies done off the California coast, citing other possibly relevant papers.
Quote
Trapped D1 internal tides are often more energetic than D2 internal tides in the SCB. These waves may have considerable impact on mixing as noted earlier (Section 1) because there are likely numerous sites of generation and dissipation in close proximity at rough topography (Tanaka et al., 2013). Elsewhere,at a sea mount in the North Pacific near 321N, dissipation is strong enough to dissipate the trapped D1 motions within 3 days, which makes for a strongly forced and damped system (Kunze and Toole,1997). In the SCB, surface drifters in this area show diurnal/inertial oscillations with decay scales of 10 days (Poulain, 1990).There are numerous sources of D2 internal tides along the continental slope and over the rough topography of the SCB(Beckenbach and Terrill, 2008; Buijsman et al., 2012). Internal tidal generation may produce local mixing (Johnston et al., 2011a;Klymak et al., 2006). Propagating internal tides may encounter topography, scatter to smaller scales, and break (Johnston and Merrifield, 2003; Johnston et al., 2003; Kelly et al., 2012; Martini et al., 2011; Nash et al., 2004)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 26, 2020, 09:57:40 PM
At last....

arctic tidal current atlas (https://www.nature.com/articles/s41597-020-00578-z.pdf)
Till M. Baumann, Igor V. Polyakov, Laurie Padman, Seth Danielson, Ilker Fer, Markus Janout, William Williams & Andrey V. Pnyushkov
Received: 17 January 2020; Accepted: 24 June 2020;Published online: 21 August 2020

Quote
Background & Summary
Tidal currents are often the dominant source of current variability and play an important role in shaping the Arctic Ocean hydrography and sea ice cover. Tidal currents are also a key element shaping the marine ecosystem with impacts ranging from creating the habitat of the intertidal zone to mixing of nutrients. Furthermore, information about tidal currents is used for many practical applications, such as navigation, fisheries and marine structures and operations.

Barotropic tidal models based on the depth-integrated momentum and continuity equations provide ocean surface height and depth-averaged currents for major tidal constituents throughout the Arctic. These comparatively simple models show very little tidal activity (<0.5 cm/s) in the central Arctic deep basins, but strong amplitudes (>10 cm/s) over portions of the continental shelves and slopes. Where barotropic tidal currents flow across steep slopes or rough topography in the presence of stratification, energy can be converted from barotropic to baroclinic (internal) tides whose energy finally dissipates in mixing processes. The importance of baroclinic tidal processes was highlighted, for example, by Luneva et al, who found that the addition of tidal currents to an atmospherically forced three-dimensional simulation reduced pan-Arctic sea ice volume by ~15%. The authors attributed this sea ice reduction to the entrainment of warm subsurface Atlantic Water into the cold near-surface waters by mixing caused by increased surface stresses and by upper-ocean shear instabilities from the combination of baroclinic tides and the atmospherically forced three-dimensional circulation. In contrast to barotropic tides, the generation, propagation and dissipation of baroclinic tidal waves are sensitive to stratification, mean flow, and energy losses through friction and mixing within the water column. They may, therefore, change substantially with variations in the background ocean state associated with weather-band and seasonal changes in forcing, ocean mesoscale variability (e.g., eddies) and as the Arctic Ocean changes on longer time scales. Despite the importance of tides for the Arctic Ocean and its sea ice, most ocean general circulation models used for climate projections do not currently include tides.


Quote
Concluding remarks.
Tidal currents play a vital role in the Arctic climate and ecosystems, but our understanding of their spatio-temporal variability is limited. The goal of our atlas of tidal currents described herein is to provide a tool that enables investigations into regional high-frequency dynamics in a changing Arctic Ocean. As a ground-truth for the modelling community, this may contribute to more reliable projections of future Arctic Ocean states.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 26, 2020, 10:22:40 PM
Internal Tides and Abyssal Mixing

M.C. Gregg, in Reference Module in Earth Systems and Environmental Sciences, 2013
Internal Tides (https://www.sciencedirect.com/topics/earth-and-planetary-sciences/barotropic-flow)   

Quote
The horizontal currents produced by surface tides are constant with depth. Called barotropic flows, they are driven by horizontal pressure gradients induced by the sea surface slopes accompanying the tides. When these currents cross sloping bottoms, the oscillations produced by disrupting the ambient stratification propagate away as internal tides, shown schematically in Figure 2. Internal tidal currents vary with depth (unlike barotropic tidal currents) and are associated with vertical displacements of 10 m or more in the thermocline. Their surface displacements, however, are reduced about 1000-fold, the ratio of the density of water and that of air.

Quote
Existence of internal tides has long been known from fluctuations of temperature observed in the thermocline with moorings. Their spatial structure and importance, however, were not generally suspected until discovered by an acoustic array north of Hawaii (Dushaw et al., 1995). This and weak signatures in records of surface displacements led Ray and Mitchum (1996) to search for large-scale patterns in sea surface heights measured with radar altimeters on Topex/Poseidon satellites. Against expectations, they were able to remove meter-scale surface tides to reveal the centimeter-scale displacements of internal tides. Ray and Mitchum discovered coherent displacements between rather widely spaced satellite tracks indicating internal tides radiating northward from the Hawaiian Ridge. Peaks in along-track spectra indicated horizontal wavelengths of 150–160 km for mode-one M2 (lunar) and S2 (solar) tides. Mode-two peaks were also detectable with wavelengths about half as long. These results led in turn to the Hawaiian Ocean Mixing Experiment (HOME) early in the twenty-first century.

This perhaps explains the eddy just east of the Lomonosov ridge posted by blumenkraft (https://forum.arctic-sea-ice.net/index.php/topic,3030.msg280937.html#msg280937) on aug13.

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=3030.0;attach=280492;image)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 26, 2020, 10:30:30 PM
worldview terra modis, yermak plateau area, aug26, heavy contrast.
click to compare with a very light contrast version

a peek through the clouds with rammb. Some eddy motion by the large floes can just be made out.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: oren on August 26, 2020, 11:46:18 PM
Uniquorn big thanks for your great contributions on this thread.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 27, 2020, 05:18:44 AM
Uniquorn big thanks for your great contributions on this thread.
+1
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 27, 2020, 05:26:02 AM
At last....
Indeed, a very good find. I've snipped two interesting parts of the text from your post:

[quote author = https://www.nature.com/articles/s41597-020-00578-z.pdf]
These comparatively simple models show very little tidal activity (<0.5 cm/s) in the central Arctic deep basins, but strong amplitudes (>10 cm/s) over portions of the continental shelves and slopes.
Quote

and further :
[quote author = https://www.nature.com/articles/s41597-020-00578-z.pdf]
The importance of baroclinic tidal processes was highlighted, for example, by Luneva et al, who found that the addition of tidal currents to an atmospherically forced three-dimensional simulation reduced pan-Arctic sea ice volume by ~15%. The authors attributed this sea ice reduction to the entrainment of warm subsurface Atlantic Water into the cold near-surface waters by mixing ...
Quote

So finally a number that allows for comparison with other processes active in the Arctic. And I'll admit it is bigger than I expected. The localized upward mixing caused by tidal movement has a pan-Arctic effect of keeping volume 15% lower than would otherwise be the case.

Since this mixing is localized, I wonder if there is a strong variability at surface, i.e. whether these ongoing upwards mixing processes have the potential to "punch through" the ice at some time in the future, making them suddenly visible.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 27, 2020, 11:55:21 PM
A quick look at the persistent low concentration area north of NSI/ESS, 80.7N 154.5

amsr2-uhh, aug17-26
today's worldview (https://go.nasa.gov/2YIyTPb) overlaid onto noaa bathymetry (https://maps.ngdc.noaa.gov/viewers/bathymetry/)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 28, 2020, 12:28:09 AM
https://go.nasa.gov/34DrtAq, nth greenland for ref (clahe 1.7)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 28, 2020, 10:58:26 PM
mercator sst with amsr2-uhh, aug1-27
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 29, 2020, 12:01:48 PM
Intriguing description of motion in the fram strait here (https://blogs.agu.org/thefield/2020/08/12/postcards-from-a-formerly-frozen-icebreaker-part-50/)

Quote
By Matthew Shupe

7/25/20 Round and Round
We are just spinning in circles around here. Around and around. Our floe just keeps on turning. Over the many days that we’ve been here the orientation of our floe didn’t change much, the ship having a robust SW heading. But in the last two days we have spun in two full circles, including about 410 degrees in just the last day! This is really remarkable, and I have no idea how it happens. Is it somehow drag on the floe due to the ship, or just dynamics in the ocean? There have not really been many winds to speak of. No one else understands this either. But it has a fascinating effect on our perspective. Standing out on the short of the floe, you look out and so many other floes go drifting by, seemingly moving quickly. While some of these floes are likely moving in reality, our spinning floe gives the impression that everything else is moving very fast. We are not used to that, as typically our floe just drifts along with everything else. Another one of those Arctic mysteries.

On jul25 they were just crossing 80N, a little east of the large rotating eddy. (weather was only clear on jul22)

  79.9   -1.0 20-07-25 15:00    6   30     -0.1  7  1  97  4042 89/9/ 1017.8
  79.9   -0.9 20-07-25 14:00    6   30      0.0  /  /  //  //// ///// 1018.2
  80.0   -0.7 20-07-25 11:00    6   10      0.0  /  /  //  //// ///// 1018.2
  80.0   -0.7 20-07-25 10:00    5   10      0.3  /  /  //  //// ///// 1018.4

(https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2906.0;attach=276910;image)

A rather messy buoys eye view of the movement. It didn't occur to me before that the floes might be spinning independently of each other. Different keels, smaller eddies...
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 29, 2020, 01:00:55 PM
It didn't occur to me before that the floes might be spinning independently of each other. Different keels, smaller eddies...

Or perhaps the larger floe that they are on is only partially entering a larger movement (eddies or currents). This would cause it to rotate and from the point of view of someone standing at the edge of the floe, smaller floes would seem to be moving away (i.e. staying in place as the observer moves past) as long as the observer is facing away from the current. So observing the smaller floes for a full 360 degrees turn of the larger would tell you more about what was going on.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 29, 2020, 01:05:41 PM
Could be.
Southerlies from the Laptev opening up some weaker areas in the CAB. The oval low concentration area persists.

added rammb of the oval area. Stationary frames left in (no cheating ;) )
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 29, 2020, 09:50:12 PM
A very close look at  axib buoy (https://forum.arctic-sea-ice.net/index.php/topic,2906.msg281391.html#msg281391) 91790, ~86.1N -45 (north of Greenland)

Somewhere near the middle of the clear worldview image (https://go.nasa.gov/31EWHp1) from aug28 

I think arctic ocean 'waking up' might not have been too far off the mark

rammb nth greenland
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 30, 2020, 05:55:22 AM
Fantastic swirling - but scale is not obvious. Based on the latitudes and longitudes at start and finish it seems that the swirling is taking place in a very small area, perhaps 1 or 2 km from side to side.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 30, 2020, 11:27:43 PM
Worldview terra modis of the low concentration area north of ESS, jul24-30
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on August 31, 2020, 06:39:05 AM
At first sight the area of open water seems persistent, but I am not convinced that it is caused by underlying processes and not vagaries of wind. For one, scale is missing making it impossble to estimate the forces involved, and secondly, the other smaller bits of low concentration seem to move at the same rate and in the same general direction.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on August 31, 2020, 11:06:05 AM
https://go.nasa.gov/32F4bYr, it takes a couple of minutes. Once an area has been selected, using the measuring tools bottom right, it stays overlayed while scrolling through the dates. The low concentration does drift somewhat, but remains north of the shelf break.

'vagaries of the wind' does not address why it is low concentration in the first place.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 04, 2020, 03:48:09 PM
The ice edge is getting very close to the Yermak plateau low concentration area.
P222 at ~82.3N 3E is just north of the ice edge. (orientation is different with 0deg down)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 08, 2020, 11:26:13 AM
gmrt bathymetry with amsr2-uhh overlay at 75% transparency. 0% concentration, normally dark blue, has been set to fully transparent. sep1-7
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 08, 2020, 02:05:41 PM
https://www.nature.com/articles/ngeo2350

Tide-mediated warming of Arctic halocline by Atlantic heat fluxes over rough topography

Tom P. Rippeth, Ben J. Lincoln, Yueng-Djern Lenn, J. A. Mattias Green, Arild Sundfjord & Sheldon Bacon
Quote
Abstract

The largest oceanic heat input to the Arctic Ocean results from inflowing Atlantic water. This inflowing water is warmer than it has been in the past 2,000 years. Yet the fate of this heat remains uncertain, partly because the water is relatively saline, and thus dense: it therefore enters the Arctic Ocean at intermediate depths and is separated from surface waters by stratification. Vertical mixing is generally weak within the Arctic Ocean basins, with very modest heat fluxes (0.05–0.3 W m−2) arising largely from double diffusion. However, geographically limited observations have indicated substantially enhanced turbulent mixing rates over rough topography. Here we present pan-Arctic microstructure measurements of turbulent kinetic energy dissipation. Our measurements further demonstrate that the enhanced continental slope dissipation rate, and by implication vertical mixing, varies significantly with both topographic steepness and longitude. Furthermore, our observations show that dissipation is insensitive to sea-ice conditions. We identify tides as the main energy source that supports the enhanced dissipation, which generates vertical heat fluxes of more than 50 W m−2. We suggest that the increased transfer of momentum from the atmosphere to the ocean as Arctic sea ice declines is likely to lead to an expansion of mixing hotspots in the future Arctic Ocean.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: colding on September 08, 2020, 02:20:36 PM
gmrt bathymetry with amsr2-uhh overlay at 75% transparency. 0% concentration, normally dark blue, has been set to fully transparent. sep1-7
Apologies for what might be a stupid question, but it is accepted lore that the stratification of the arctic ocean over the deep water, prevents the relatively hot and salty waters of the deep from reaching the surface. This makes it comparatively easy to refreeze the surface each vinter.

Now, however, we see two large regions of deep water, which has been ice free for some time.

How long does it takes to destroy the halocline over those areas and have a well-mixed ocean?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 08, 2020, 04:10:49 PM
Quote
How long does it takes to destroy the halocline over those areas and have a well-mixed ocean?
Quick answer. I don't know. I try to analyse what is happening now, presently attempting to link low concentration areas with possible turbulence.
whoi itp114 (https://www.whoi.edu/page.do?pid=165196) and other active itp's give us an idea of what is happening in the middle of the Beaufort today. Thermocline/halocline are still there. Temperature at 5m is ~-1C. Temperature at 50m looks to be on the high side but I haven't done a thorough yearly comparison. You could go back through the years (https://www.whoi.edu/page.do?pid=23099) and document the beaufort buoys. A few members would be very grateful and the data might give you a trend to work from.
Hopefully mosaic will deploy another itp near the pole to give us something to compare regarding atlantification.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 08, 2020, 05:45:43 PM
Now, how long does it take for laptev water to reach the yermak plateau/north of Greenland?
my bolds
Quote
Cross-correlation analysis of time series of AW temperature measured at 250 m from 1997–2018 in Fram Strait, the entry point of AW into the Arctic, and from 2002–18 in the eastern EB (red time series in Fig. 5a) shows the strongest correlation, R = 0.67, for a lag of 682 days (Fram Strait series leads; Fig. 5b). The fit between the two time series is better over the last 7–8 years than it is over the earlier period. The ~2-yr lag suggests that warm pulses of AW that entered the Arctic Ocean through Fram Strait are traveling toward the eastern EB at a speed 2–2.5 times faster than that estimated for a warm AW pulse that entered the eastern EB in 2004 (Polyakov et al. 2005). This implies that the rate of advection has increased over time. However, noisy data due to gaps in the EB record preclude meaningful statistical analysis using just the early part of the time series. Assuming that the lagged correlation between the two time series will persist in the near future, the latest part of the Fram Strait series (not shown) implies that the AW temperature in the eastern EB reached its peak in late 2018 (these data are not yet available) and will slowly decrease over the next 1–2 years.

Does it take 2 years to get back to the north of Greenland?

Quote
Composite 2002–18 time series of (a) monthly mean potential water temperature θ and (c) daily depth of the lower halocline boundary Hbase defined by the 0°C isotherm at the M14 mooring location (for location, see Fig. 2). (b) Comparison of deseasonalized monthly mean time series of normalized θ anomalies from 250 m of the M14 mooring of the eastern EB (EEB) relative to F2–F3 moorings of Fram Strait lagged by 678 days (as obtained from correlation analysis); time series are normalized by their standard deviations.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Tor Bejnar on September 08, 2020, 06:40:08 PM
https://www.nature.com/articles/ngeo2350

Tide-mediated warming of Arctic halocline by Atlantic heat fluxes over rough topography

Tom P. Rippeth, Ben J. Lincoln, Yueng-Djern Lenn, J. A. Mattias Green, Arild Sundfjord & Sheldon Bacon
...
Is it reasonable to connect what this paper (well, abstract) says (Atlantic water heat and vertical mixing associated with tides and topography) with the partly melted out CAA-Greenland mega crack? 
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 08, 2020, 10:38:09 PM
I think there's a good case for the low concentration area north of the Yermak plateau. North of Ellesmere Island looks like coastal upwelling which is the ultimate rough topography. North of Greenland? Surprising there is not more discussion. It's rough topography but with returning AW. Hardly any recent data. It's a shame that itp116 profiler failed before it passed right over that area. (failed at 88.3N on new years day). Mosaic was all further east.
So it's a reasonable connection but some may not be convinced  ;)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on September 09, 2020, 06:48:14 AM
It seems that this whole tidal turbulence and upwelling aspect of Arctic waters is a ripe field for investigation. I agree with uniqorn, and I think I mentioned this before, but these turbulences (wherever they may be found) could be on the brink of "punching through" the overlying ice in summer in various locations, possibly starting a cascading breakdown of the halocline and "oceanification" in the middle of the pack?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on September 09, 2020, 02:03:08 PM
On the north coast of south America, flow is dominated by large eddies. Easterly and ENE winds howl through the southern Caribbean sea causing upwelling in some areas on the shelf margin and driving what would be a warm current towards the west and WNW. The Coriolis effect makes normal current flow impossible so large eddies form transporting water westwards and somewhat northwards across the Caribbean and into the Gulf of Mexico.

This doesn't happen north of Greenland but if persistent high pressure existed at the north pole eddies might spin from the Fram into the waters north of Greenland carrying warm salty water into the region dominated by cold fresh water. Could that have happened this summer?

As I wrote over at the MOSAiC thread, I wish they had deployed a grid full of buoys to study what's happening between Greenland and the pole.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on September 09, 2020, 02:47:43 PM
... I wish they had deployed a grid full of buoys to study what's happening between Greenland and the pole.
Second that!
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: FishOutofWater on September 09, 2020, 04:35:56 PM
Tor there are papers about how Atlantic water has been getting under glaciers on the east coast of Greenland in recent years. After the shelf ice is gone, tides and eddies cause more mixing. This may be happening on the N coast of Greenland. There are multiple topographic highs under water where they could induce increased mixing after ice shelves melted and rates of flow increased.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 12, 2020, 03:22:11 PM
mercator 0m salinity(SSS), jun1-sep11
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: nanning on September 12, 2020, 06:57:09 PM
Great animations you've provided uniquorn, thank you. The first link is just an image of the colour scale if I open it.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 12, 2020, 10:04:20 PM
yes, I used to get told off for posting animations without the scale but including it in the animation makes the file size larger so I post it separately, if I remember. hmm
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: interstitial on September 12, 2020, 10:10:54 PM
yes, I used to get told off for posting animations without the scale but including it in the animation makes the file size larger so I post it separately, if I remember. hmm
thanks for including the scale it helps your method seems like a good compromise
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 12, 2020, 10:57:14 PM
mercator 34m salinity, jun1-sep11
Mercator not showing anything unusual north of greenland at 34m (short term)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 13, 2020, 10:29:48 PM
nsidc ice age update
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 17, 2020, 05:09:01 PM
Signs of turbulence north east end of the yermak plateau. https://go.nasa.gov/3iLPHNq
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 19, 2020, 09:58:07 PM
mosaic iabp buoy names and relative locations for ref
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 19, 2020, 10:38:32 PM
@Bruce Steele, whoi itp117 (https://www.whoi.edu/page.do?pid=165197) temperature spike on SAMI
edit: similar spike on itp105, Mackenzie river water?
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 20, 2020, 09:42:39 PM
https://go.nasa.gov/2ZWcTAS for ref
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Bruce Steele on September 20, 2020, 10:50:43 PM
 
The averaged salinity in the global ocean is  35.5 PSU, varying from less than 15 PSU at the mouth of the rivers to more than 40 PSU in the Dead Sea.

Uniquorn
So I was thinking ITP 105 had melted out and was sending questionable info. When I saw PSU at less than 20 I wasn’t thinking Mackenzie water. Then ITP 117 hit warm water. Too bad ITP 117 doesn’t  have salinity.  The other ITP buoys seem to be getting colder.

Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 20, 2020, 11:14:07 PM
I hoped dissolved oxygen on 117 might mean more to you than it does to me. Actually it could be a battery problem, it has been going for a year.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 21, 2020, 08:46:01 PM
Thanks to u300673 for this great article from 2012
Sea ice inertial oscillations in the Arctic Basin
F. Gimbert, D. Marsan, J. Weiss, N. C. Jourdain, and B. Barnier
https://tc.copernicus.org/articles/6/1187/2012/tc-6-1187-2012.pdf
Quote
As observed from buoy drift data, the sea ice  mean  speed  over  the  Arctic  increased  at  a  rate  of  9% per decade from 1979 to 2007, whereas the mean deformation rate increased by more than 50 % per decade over the same period (Rampal et al.,2009). These two aspects of recent sea ice evolution, i.e. strong decline in terms of ice extent and thickness, and accelerated kinematics, are strongly coupled within the albedo feedback loop. Increasing deformation means increasing fracturing, hence more lead opening and a decreasing albedo (Zhang et al.,2000). As a result, ocean warming, in turn, favours sea ice thinning in summer  and  delays  refreezing  in  early  winter,  i.e.  strengthens sea ice decline. This thinning should decrease the mechanical strength, therefore allowing even more fracturing, hence larger speed and deformation. A consequence is the acceleration of the export of sea ice through Fram Strait, with a significant impact on sea ice mass balance (Rampal et al.,2009,2011; Haas et al.,2008), and ice age (Nghiem et al.,2007). Moreover, sea ice mechanical weakening decreases the likelihood of arch formation along Nares Strait, therefore allowing old, thick ice to be exported through this strait (Kwok et al.,2010).
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: A-Team on September 21, 2020, 09:17:42 PM
Might take a look at the 2009 L Kalescke paper as he could be available to answer questions. Prolific sea ice expert R Kwok has also been on this since forever. Some of these papers could only base on 3 hr sampling whereas with the buoys of today, hourly or even half-hourly GPS reports are the rule. What's more, the GPS is a lot more accurate today. Tides in the central Arctic have period ½M2 or 12hr 42min.

Observation of cyclone-induced inertial sea-ice oscillation in Fram Strait
A Lammert B Brummer and L. Kaleschke

In this paper we present measurements of an intense cyclone, which occurred during FRAMZY 2007. The cyclone moved very fast from south to north through the Fram Strait and caused substantial inertial ice-motions lasting for several days. Inertial sea-ice oscillations are a known process both in the Arctic and the Antarctic. However, to the authors’ knowledge no observations of such a strong inertial oscillation in the Arctic have been presented in the literature before.

Sub-daily sea ice motion and deformation from RADARSAT observations
R Kwok  GF Cunningham WD Hibler 2003
https://trs.jpl.nasa.gov/bitstream/handle/2014/37327/03-2404.pdf?

We find a persistent level of oscillatory sea ice motion and deformation, superimposed on the large-scale wind-driven field, in May 2002 (spring) and February 2003 (midwinter), in the high Arctic over a region centered at (85N, 135W). At this latitude, the RADARSAT wide-swath SAR coverage provides 4 – 5 sequential observations every day, for ice motion retrieval, with a sampling interval at the orbital period of 101 minutes. Periodic correlations in ice motion and deformation can be seen in length scales from 10 km and above, and suggest a 12-hr oscillation that is more likely associated with inertial rather than tidal frequencies.

https://scholar.google.com/citations?hl=en&user=OtzTNwkAAAAJ&view_op=list_works&sortby=pubdate

Internal wave observations from the Arctic environmental drifting buoy
AJ Plueddemann August 1992

Near-Inertial Internal Gravity Waves in the Ocean
MHAlford et al
https://www.annualreviews.org/doi/abs/10.1146/annurev-marine-010814-015746

We review the physics of near-inertial waves (NIWs) in the ocean and the observations, theory, and models that have provided our present knowledge. NIWs appear nearly everywhere in the ocean as a spectral peak at and just above the local inertial period f, and the longest vertical wavelengths can propagate at least hundreds of kilometers toward the equator from their source regions; shorter vertical wavelengths do not travel as far and do not contain as much energy, but lead to turbulent mixing owing to their high shear. NIWs are generated by a variety of mechanisms, including the wind, nonlinear interactions with waves of other frequencies, lee waves over bottom topography, and geostrophic adjustment; the partition among these is not known, although the wind is likely the most important. NIWs likely interact strongly with mesoscale and submesoscale motions, in ways that are just beginning to be understood.
 
See also:

"W Munk: It was to be thirty years until Rob Pinkel showed that arctic observations were inconsistent with the assumed factoring of the spectrum. By then Chris had gotten nervous and claimed that the G in GM referred to his great uncle Arthur Garrett. A few years later Pinkel demonstrated that one could go a long way with just two Doppler-smeared spectral lines: the M2 tidal frequency and the local inertial frequency. Here I refer to the smearing of the spatial fine structure by the vertical orbital motion of the long internal waves"

https://www.researchgate.net/profile/R_Pinkel/publications
https://link.springer.com/chapter/10.1007%2F978-3-642-12087-9_7
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 21, 2020, 10:29:13 PM
Overview of iabp buoys, will be taking a closer look at some of them tomorrow
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 22, 2020, 02:23:37 PM
Overview of available iabp buoys north of Greenland and a closer animation of 300234065497190, 300234068810610 and 300234068027940.
csv data attached as text.

https://betterexplained.com/articles/an-interactive-guide-to-the-fourier-transform/
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: A-Team on September 22, 2020, 08:53:17 PM
Go through enough journal articles and eventually ones will show up that actually explain near-inertial waves and the history of their research. Note too F Gimbert fired off a small burst of articles on this, not just the one above.

Dynamics of the Changing Near-Inertial Internal Wave Field in the Arctic Ocean
Hayley V. Dosser; Luc Rainville
J. Phys. Oceanogr. (2016) 46 (2): 395–415.
https://journals.ametsoc.org/jpo/article/46/2/395/12534

'The dynamics of the wind-generated near-inertial internal wave field in the Canada Basin of the Arctic Ocean are investigated using the drifting Ice-Tethered Profiler dataset for the years 2005 to 2014, during a decade when sea ice extent and thickness decreased dramatically. This time series, with nearly 10 years of measurements and broad spatial coverage, is used to quantify a seasonal cycle and inter-annual trend for internal waves in the Arctic, using estimates of the amplitude of near-inertial waves derived from isopycnal displacements.

'The internal wave field is found to be most energetic in summer when sea ice is at a minimum, with a second maximum in early winter during the period of maximum wind speed.

'The standard picture of Arctic internal waves derives from observations made during the 1980s and 1990s [e.g., the Arctic Internal Waves Experiment (AIWEX) in spring of 1985 (Levine et al. 1987; D’Asaro and Morehead 1991; Merrifield and Pinkel 1996) and the Surface Heat Budget of the Arctic Experiment (SHEBA) in 1997 to 1998 (Pinkel 2005)], which found a quiescent Arctic Ocean with an internal wave field energy level an order of magnitude or more below that at lower latitudes (Levine et al. 1985, 1987).

'Low internal wave energy levels in the Arctic are attributed to the presence of sea ice, which causes dissipation of internal waves in the under-ice surface boundary layer, limiting energy propagation across the Arctic (Morison et al. 1985; Pinkel 2005; Fer 2014). It has been suggested that sea ice impedes momentum transfer from the wind to the water column (Plueddemann et al. 1998), with ice deformation being of more importance to internal wave generation (Halle and Pinkel 2003).

'Most of the energy in the internal wave field is contained in the near-inertial frequency band, from roughly f–1.1f, where f is the local Coriolis or inertial frequency (Garrett and Munk 1972; Garrett 2001). In the Arctic Ocean, observations of the internal wave spectrum show the expected peak at the inertial frequency (Halle and Pinkel 2003; Fer 2014; Cole et al. 2014). Near-inertial internal waves can be generated whenever wind stress resonantly forces the air–ice or air–water interface at or near the inertial frequency. In the Northern Hemisphere, anticyclonic or clockwise inertial oscillations are set up in the sea ice and mixed layer.

These purely horizontal oscillations create disturbances at the base of the mixed layer, generating a freely propagating near-inertial wave in the stratified water column below (D’Asaro 1985). The result is vertical propagation of energy through the water column to depths at which the internal waves can become unstable and break (Gregg et al. 1986; Hebert and Moum 1994).

'Near-inertial internal waves can also be generated as a result of the motion of drifting sea ice. The rough bottom of the ice impulsively forces the water column, or there may be horizontal variations in bottom roughness that cause vertical motion of the fluid below. This results in a pattern of forcing related to ice roughness and ice–ocean drag that is moving at the velocity of the sea ice, which can generate internal waves (McPhee and Kantha 1989) with horizontal and spatial scales consistent with observations of near-inertial waves in the Arctic Ocean (D’Asaro and Morehead 1991).'


Recent mechanical weakening of the Arctic sea ice cover
as revealed from larger inertial oscillations
F Gimbert NC Jourdain D Marsan J Weiss B. Barnier

Our approach, performed at the basin and multi-decadal scales from the International Arctic Buoy Programme (IABP) data set, consists in the analysis of the response of sea ice to the well-defined Coriolis force. As this specific forcing is constant over time, an evolution of the response, i.e., of ice motion around the inertial frequency f0 ≈ 2 cycles.d1 within the arctic basin, would be a signature of a change in the mechanical behavior of the ice cover.

Ww performed a statistical analysis of the magnitude of inertial motion, relatively to the norm of the velocities, and revealed spatial and seasonal patterns in agreement with the corresponding ice concentration and thickness patterns, i.e., inertial motion is more pronounced in regions (Beaufort Sea, eastern Arctic) and seasons (summers) where ice is thinner and less concentrated. This analysis also revealed a significant strengthening of ice inertial motion at the basin scale, in both summer and winter, in recent years.

This evolution, we suggested, is likely to be the signature of a mechanical weakening of the ice cover and a decrease of the magnitude of internal stresses. This analysis, however, did not allow to differentiate precisely the direct effect of ice thinning, the effect of a possible modification of vertical penetration of turbulent momentum within the ocean boundary layer, or that of an actual mechanical weakening, onto this strengthening of inertial motion.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 23, 2020, 11:54:58 PM
Thanks for those articles.

2 new whoi itp buoys (https://www.whoi.edu/page.do?pid=166916), 120 and 121
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on September 25, 2020, 12:01:58 PM
Images of the area of 'flash freezing' in the Beaufort.
Worldview terra modis true colour (adaptive contrast) with amsr2-awi-v103 overlay
Polarview S1B with worldview true colour overlay (click)
A cropped comparison of 2 small areas of interest.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Glen Koehler on September 29, 2020, 03:07:10 AM
Ocean Stratification is Not Good News. Very Not Good.
https://climatecrocks.com/2020/09/28/ocean-stratification-is-not-good-news-very-not-good/ (https://climatecrocks.com/2020/09/28/ocean-stratification-is-not-good-news-very-not-good/)

"This seemingly technical finding has profound and troubling implications. The more stable the upper ocean, the less vertical mixing that takes place. This mixing is a primary means by which the ocean buries warming surface waters. So the surface warms up even faster. It’s what we call a “positive feedback”—a vicious cycle."

"Our study suggests that key positive feedbacks (amplifying factors) related to reduced ocean heat might lead to more rapid surface warming in the decades ahead than many of the models predict."
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Freegrass on October 01, 2020, 08:42:30 PM
The next step in my evolution is learning more about salinity. But I don't know how the read Uniquorn's graphs... I'm unable to visualize it...

Isn't there a way to turn the Mercator 2D images into a 3D graphical presentation? They have salinity at all levels, so isn't it possible to use that data to create something like this?

https://youtu.be/KTg6g59XjVo (https://youtu.be/KTg6g59XjVo)
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 02, 2020, 05:21:52 PM
Nice. Underwater waterfalls.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Glen Koehler on October 02, 2020, 07:15:13 PM
The next step in my evolution is learning more about salinity. But I don't know how the read Uniquorn's graphs... I'm unable to visualize it...

Isn't there a way to turn the Mercator 2D images into a 3D graphical presentation? They have salinity at all levels, so isn't it possible to use that data to create something like this?

https://youtu.be/KTg6g59XjVo (https://youtu.be/KTg6g59XjVo)
    That would make a lovely live-feed wallscreen animation for NSIDC headquarters.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: Freegrass on October 03, 2020, 07:27:45 AM
Nice. Underwater waterfalls.
Saltwaterfalls...

There are more visualisations on their YouTube page.

CEN Climate Visualization Laboratory
https://www.youtube.com/user/KlimaCampus/videos (https://www.youtube.com/user/KlimaCampus/videos)

https://www.cen.uni-hamburg.de/en/facilities/visualization.html
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 03, 2020, 01:34:08 PM
It's not just the salinity, Atlantic water returning from the Arctic Ocean is also cooler with higher density.

Key Physical Variables in the Ocean: Temperature, Salinity, and Density (https://www.nature.com/scitable/knowledge/library/key-physical-variables-in-the-ocean-temperature-102805293/)

(https://www.nature.com/scitable/content/ne0000/ne0000/ne0000/ne0000/102810810/1_2.jpg)
Quote
Figure 1: A vertical profile of temperature and salinity at 39°N, 152°W in the North Pacific (data courtesy of the CLIVAR and Carbon Hydrographic Data Office, cchdo.uscd.edu).
a) Vertical profiles of in-situ temperature t, potential temperature θ, and Conservative Temperature Θ. Inset shows an expanded view of deep ocean values. Potential and Conservative temperature are within 0.0003°C in the deep ocean. Note that heat content (proportional to Θ) actually decreases with depth, but pressure effects cause a rise in the in-situ temperature t. b) Vertical profiles of Practical Salinity SP (with no units), Reference Salinity SR, and Absolute Salinity SA. c) Vertical profiles of in-situ density (σ), potential density referenced to the sea surface (σθ), and potential density referenced to 4000 dbar (σ4). Most of the in-situ density increase with depth is due to pressure effects, which are removed in the calculation of potential densities, showing how weakly stratified the ocean actually is.
© 2013 Nature Education All rights reserved. View Terms of Use

or a simpler way of looking at it, though not that relevant to the arctic.

Also an 'interesting' section of itp110 drift path showing how density changes with temperature and salinity, 7m-80m from 2019, day123-218 (best viewed at half speed)
density green, temperature purple, salinity red
temp    -1.8 to 0.6C
salinity  27.5 to 31.2
density 1021.5 to 1025kg/m^3

http://www.csgnetwork.com/water_density_calculator.html
Quote
The equation used in this calculator can be found in:
Millero, F, C. Chen, A Bradshaw, and K. Schleicher, 1980: A new high pressure equation of state for seawater, Deep Sea Research, Part A, 27, 255-264.
doi:10.1080/15210608209379435

It would be nice to have someone else check the calculations:
Quote
function CalcDen(form) {
//function sig=sigma(p,t,s)

// calculates in situ density.
// millero et al 1980, deep-sea res.,27a,255-264
// jpots ninth report 1978,tenth report 1980
// units:
//       pressure        p        decibars
//       temperature     t        deg celsius (ipts-68)
//       salinity        s        nsu (ipss-78)
//                       sigma    (10.**-3)g/cm**3
//
// r. schlitzer  (5/18/89)


var p = document.denform.pressure.value;
var t = document.denform.temp.value;
var s = document.denform.conc.value;
// change pressure from input units of decibars to bars
// square root salinity.
p=p/10;sr= Math.sqrt(Math.abs(s));
// density pure water at atm press in kg/m3 = (10**-3)gm/cm3
r1=((((6.536332e-9*t-1.120083e-6)*t+1.001685e-4)*t-9.095290e-3)*t+6.793952e-2)*t- .157406;
// seawater density atm press.
r2=(((5.3875e-9*t-8.2467e-7)*t+7.6438e-5)*t-4.0899e-3)*t+0.824493;
r3=(-1.6546e-6*t+1.0227e-4)*t-5.72466e-3; r4=4.8314e-4;
sig=(r4*s + r3*sr + r2)*s + r1;
// compute compression terms
e=(9.1697e-10*t+2.0816e-8)*t-9.9348e-7;
bw=(5.2787e-8*t-6.12293e-6)*t+8.50935e-5; b=bw+e*s;
c=(-1.6078e-6*t-1.0981e-5)*t+2.2838e-3;
aw=((-5.77905e-7*t+1.16092e-4)*t+1.43713e-3)*t+3.239908;
a=(1.91075e-4*sr+c)*s+aw;
b1=(-5.3009e-4*t+1.6483e-2)*t+7.944e-2;
a1=((-6.1670e-5*t+1.09987e-2)*t-0.603459)*t+54.6746;
kw=(((-5.155288e-5*t+1.360477e-2)*t-2.327105)*t+148.4206)*t+19652.21;
k0=(b1*sr+a1)*s+kw;
// evaluate pressure polynomial and return
k=(b*p+a)*p+k0;
sig=(k*sig+1000*p)/(k-p);
// sig remains unchanged since is (10**-3)gm/cm**3
document.denform.density.value = perRound(sig+1000);
}
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 14, 2020, 01:06:31 PM
Tidally Forced Lee Waves Drive Turbulent Mixing Along the Arctic Ocean Margins
Ilker Fer, Zoé Koenig, Igor E. Kozlov, Marek Ostrowski, Tom P. Rippeth,, Laurie Padman, Anthony Bosse, Eivind Kolås
First published: 06 August 2020

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL088083

Quote
Abstract

In the Arctic Ocean, limited measurements indicate that the strongest mixing below the atmospherically forced surface mixed layer occurs where tidal currents are strong. However, mechanisms of energy conversion from tides to turbulence and the overall contribution of tidally driven mixing to Arctic Ocean state are poorly understood. We present measurements from the shelf north of Svalbard that show abrupt isopycnal vertical displacements of 10–50 m and intense dissipation associated with cross‐isobath diurnal tidal currents of ∼0.15 m s−1. Energy from the barotropic tide accumulated in a trapped baroclinic lee wave during maximum downslope flow and was released around slack water. During a 6‐hr turbulent event, high‐frequency internal waves were present, the full 300‐m depth water column became turbulent, dissipation rates increased by a factor of 100, and turbulent heat flux averaged 15 W m−2 compared with the background rate of 1 W m−2.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: binntho on October 14, 2020, 03:25:53 PM
Interesting article, Uniqorn. It is clear that turbulence mixing caused by tidal currents + bathymetry are a significant factor in the transfer of heat verticaly. But what strikes me is the extremely low speed of 0.15 m/s - only one tenth of normal walking speed. But then again, the volume must be large.
Title: Re: Arctic Ocean salinity, temperature and waves
Post by: uniquorn on October 23, 2020, 04:18:24 PM
amsr2, awi dev v103 overlaid onto mercator 0m ocean temperature and salinity, sep4-oct22  (8MB)
Combined these two ani's from the freezing season thread to make it easier to compare daily changes.